Acetaminophen Hepatotoxicity

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Classifications

Harrison's Part

🔗

Mappings

MONDO

MONDO:0018741 paracetamol poisoning

MONDO:0018741 is the closest chemical-specific concept, but it includes poisoning presentations without established hepatotoxicity.

MONDO:0005359 drug-induced liver injury Not Yet Curated

Acetaminophen hepatotoxicity is the intrinsic, dose-dependent subtype of the broader drug-induced liver injury concept.

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Definitions

1

Hepatotoxicity-focused clinical scope

Acetaminophen hepatotoxicity is acute hepatocellular injury attributable to a toxic acetaminophen exposure, arising after an acute ingestion or repeated supratherapeutic use and ranging from aminotransferase elevation to acute liver failure. A detectable exposure without liver injury is not by itself the disease state modeled here.

CASE_DEFINITION Disease-level clinical framing for intrinsic acetaminophen liver injury

Show evidence (2 references)

PMID:36670547 SUPPORT Other

"APAP overdose may lead to fatal acute liver injury."

The review directly links overdose to the hepatic injury defining this record.

PMID:37552484 SUPPORT Other

"single or repeated ingestion of acetaminophen"

The consensus establishes both acute and repeated-ingestion exposure patterns as clinically relevant.

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Subtypes

3

Acute immediate-release ingestion within 24 hours

An acute ingestion can include one or more doses presenting within 24 hours of the initial ingestion. For an immediate-release exposure with a known start time, a properly timed serum concentration can be interpreted with the Rumack-Matthew nomogram.

Show evidence (2 references)

PMID:40047505 SUPPORT Other

"Acute ingestion is defined as any ingestion presenting within 24 h of initial ingestion, regardless of ingestion pattern."

The consensus definition prevents multiple doses within the first 24 hours from being misclassified as repeated supratherapeutic ingestion.

PMID:34053705 SUPPORT Other

"The acetaminophen nomogram is used to assess the need for treatment in acute immediate-release overdoses with a known time of ingestion."

The review defines the acute immediate-release scenario in which nomogram interpretation is appropriate.

Modified-release acute ingestion

Acute ingestion of a modified- or extended-release formulation can produce delayed absorption and requires a different assessment pathway from a conventional immediate-release ingestion.

Show evidence (2 references)

PMID:34053705 SUPPORT Other

"scenarios that require different management pathways include modified-release"

The review explicitly separates modified-release exposure from the standard nomogram pathway.

PMID:28421844 SUPPORT Human Clinical

"we identified 73 modified-release paracetamol exposures treated with acetylcysteine"

A human cohort documents the modified-release exposure pattern and liver-injury follow-up.

Repeated supratherapeutic ingestion

Excess acetaminophen accumulated over an exposure period of 24 hours or more. This is distinct from an acute ingestion presenting within 24 hours of its start and requires a separate assessment pathway.

Show evidence (2 references)

PMID:40047505 SUPPORT Other

"Repeated supratherapeutic ingestion is defined as an exposure that occurs over a period of 24 h or more."

The consensus directly defines the duration separating repeated supratherapeutic from acute ingestion.

PMID:37552484 SUPPORT Other

"The panel developed guidelines for emergency department management of single or repeated ingestion of acetaminophen."

The consensus treats repeated ingestion as a distinct clinical assessment pathway.

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Mechanistic Hypotheses

2

Canonical NAPQI-Mitochondrial Necrosis Model

canonical_napqi_mitochondrial_necrosis_model CANONICAL

Evidence balance 2 support

Supratherapeutic acetaminophen increases NAPQI formation beyond glutathione detoxification capacity. Glutathione depletion and mitochondrial protein adduction initiate mitochondrial oxidant and peroxynitrite stress with JNK amplification. Mitochondrial permeability transition and release of endonucleases cause nuclear DNA fragmentation and centrilobular oncotic hepatocyte necrosis, which can progress to acute liver failure.

Pathograph links

Supratherapeutic Acetaminophen Exposure -> NAPQI Formation, Protein Adduction, and Glutathione Depletion DIRECT Excess acetaminophen increases formation of NAPQI beyond glutathione detoxification capacity.

Supratherapeutic Acetaminophen Exposure -> Nausea and vomiting INDIRECT UNKNOWN INTERMEDIATES Acute toxic exposure can produce nonspecific nausea and vomiting before liver injury is clinically apparent.

NAPQI Formation, Protein Adduction, and Glutathione Depletion -> Mitochondrial Oxidant Stress and JNK Amplification DIRECT Mitochondrial protein adduction and glutathione loss initiate oxidant stress and a self-amplifying mitochondrial injury program.

Mitochondrial Oxidant Stress and JNK Amplification -> Mitochondrial Permeability Transition and Nuclear DNA Fragmentation DIRECT Sustained mitochondrial stress promotes organelle failure and release of endonucleases that fragment nuclear DNA.

Mitochondrial Oxidant Stress and JNK Amplification -> Metabolic acidosis INDIRECT KNOWN INTERMEDIATES In exceptionally large overdoses, early mitochondrial dysfunction can produce severe metabolic and lactic acidosis before hepatic failure.

Mitochondrial Permeability Transition and Nuclear DNA Fragmentation -> Centrilobular Oncotic Hepatocyte Necrosis DIRECT Irreversible mitochondrial failure and nuclear DNA fragmentation culminate in oncotic hepatocyte necrosis.

Centrilobular Oncotic Hepatocyte Necrosis -> Acetaminophen-Induced Acute Liver Injury and Failure INDIRECT KNOWN INTERMEDIATES Extensive hepatocyte loss reduces hepatic synthetic, metabolic, and detoxifying capacity and can culminate in acute liver failure.

Centrilobular Oncotic Hepatocyte Necrosis -> Elevated hepatic transaminases DIRECT Necrotic liver injury is accompanied by increased plasma aminotransferase activity.

Acetaminophen-Induced Acute Liver Injury and Failure -> Acute hepatic failure DIRECT Severe injury crosses into loss of hepatic synthetic and detoxifying function.

Acetaminophen-Induced Acute Liver Injury and Failure -> Jaundice DIRECT Severe loss of hepatic function may impair bilirubin handling and produce jaundice.

Acetaminophen-Induced Acute Liver Injury and Failure -> Prolonged prothrombin time DIRECT Loss of hepatic clotting-factor synthesis prolongs prothrombin time and increases INR.

Acetaminophen-Induced Acute Liver Injury and Failure -> Hepatic encephalopathy INDIRECT KNOWN INTERMEDIATES Failure of hepatic detoxification and systemic metabolic disturbance produce hepatic encephalopathy.

Acetaminophen-Induced Acute Liver Injury and Failure -> Acute kidney injury INDIRECT KNOWN INTERMEDIATES Acetaminophen-induced acute liver failure can be complicated by acute kidney injury as part of systemic critical illness.

Acetaminophen-Induced Acute Liver Injury and Failure -> Shock INDIRECT KNOWN INTERMEDIATES Systemic inflammatory and circulatory failure can produce hypotension requiring vasopressor support.

Acetaminophen-Induced Acute Liver Injury and Failure -> Increased intracranial pressure INDIRECT KNOWN INTERMEDIATES Severe hepatic encephalopathy can progress through cerebral edema to intracranial hypertension.

Show evidence (2 references)

PMID:36670547 SUPPORT Other

"APAP-induced hepatotoxicity (AIH) is mainly caused by the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI),"

The review identifies NAPQI as the proximal toxic metabolite.

PMID:38265880 SUPPORT Other

"Mitochondria-derived endonucleases trigger nuclear DNA fragmentation, the point of no return for cell death."

The review supplies the mitochondrial-to-necrosis commitment step.

Sterile Inflammation Injury-Repair Context Model

sterile_inflammation_injury_repair_model ALTERNATIVE

Evidence balance 2 support

Necrotic hepatocytes release damage signals that activate Kupffer cells, monocyte-derived macrophages, and neutrophils. This response is established, but its net role is context-dependent: inflammatory signaling can accompany injury while immune cells also participate in debris clearance and repair. The graph therefore does not encode sterile inflammation as an invariably injurious linear amplifier.

Pathograph links

Centrilobular Oncotic Hepatocyte Necrosis -> Sterile Inflammatory and Regenerative Response DIRECT Necrotic hepatocytes release damage signals that activate innate immune cells involved in injury containment and repair.

Show evidence (2 references)

PMID:38265880 SUPPORT Other

"sterile inflammation in injury and repair with activation of Kupffer cells, monocyte-derived macrophages, and neutrophils"

The review explicitly frames the response as participating in both injury and repair.

PMID:35024303 SUPPORT Other

"the critical roles of drug metabolism, mitochondrial dysfunction, necrotic cell death, autophagy and the sterile inflammatory response"

The model review supports biological relevance while warning that interpretation requires care.

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Pathophysiology

7

Supratherapeutic Acetaminophen Exposure

Acute overdose or repeated supratherapeutic ingestion exceeds safe conjugative handling and supplies acetaminophen for increased oxidative metabolism.

Canonical NAPQI-Mitochondrial Necrosis Model

Downstream

NAPQI Formation, Protein Adduction, and Glutathione Depletion Excess acetaminophen increases formation of NAPQI beyond glutathione detoxification capacity.

Nausea and vomiting Acute toxic exposure can produce nonspecific nausea and vomiting before liver injury is clinically apparent.

Show evidence (1 reference)

PMID:36670547 SUPPORT Other

"APAP overdose may lead to fatal acute liver injury."

The review identifies overdose as the initiating exposure.

NAPQI Formation, Protein Adduction, and Glutathione Depletion

CYP2E1-mediated oxidative metabolism generates NAPQI. When glutathione-dependent detoxification is overwhelmed, NAPQI depletes glutathione and forms protein adducts, including adducts on mitochondrial proteins.

Canonical NAPQI-Mitochondrial Necrosis Model

hepatocyte CL:0000182

CYP2E1 hgnc:2631

xenobiotic metabolic process GO:0006805 ↑ INCREASED

liver UBERON:0002107

Downstream

Mitochondrial Oxidant Stress and JNK Amplification Mitochondrial protein adduction and glutathione loss initiate oxidant stress and a self-amplifying mitochondrial injury program.

Show evidence (2 references)

PMID:36670547 SUPPORT Other

"APAP-induced hepatotoxicity (AIH) is mainly caused by the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI),"

The review establishes NAPQI as the proximal toxic metabolite.

PMID:24905542 SUPPORT In Vitro

"early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria)"

Primary human hepatocytes directly demonstrate cellular and mitochondrial protein adduction.

Mitochondrial Oxidant Stress and JNK Amplification

Mitochondrial adduct stress promotes superoxide and peroxynitrite formation. Stress-kinase signaling, including JNK translocation to mitochondria, amplifies the oxidant burden and impairs mitochondrial respiration. JNK evidence is strongest in experimental human hepatocytes and preclinical systems rather than controlled in-vivo human perturbation.

Canonical NAPQI-Mitochondrial Necrosis Model

hepatocyte CL:0000182

response to oxidative stress GO:0006979 ↑ INCREASED

mitochondrion GO:0005739

Downstream

Mitochondrial Permeability Transition and Nuclear DNA Fragmentation Sustained mitochondrial stress promotes organelle failure and release of endonucleases that fragment nuclear DNA.

Metabolic acidosis In exceptionally large overdoses, early mitochondrial dysfunction can produce severe metabolic and lactic acidosis before hepatic failure.

Show evidence (3 references)

PMID:36670547 SUPPORT Other

"Mitochondrial oxidative stress and dysfunction are the major cellular events associated with APAP-induced liver injury."

The review identifies this mitochondrial program as a central event.

PMID:22378043 SUPPORT Human Clinical

"Peak GDH activity and mtDNA concentration were increased in plasma from patients with abnormal LT."

Human overdose samples provide direct biomarker evidence of mitochondrial damage in patients with liver injury.

PMID:24905542 SUPPORT In Vitro

"triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria"

Primary human hepatocytes support the JNK amplification step.

Mitochondrial Permeability Transition and Nuclear DNA Fragmentation

Oxidant-driven permeability transition collapses mitochondrial function and permits mitochondria-derived endonucleases to reach the nucleus, where DNA fragmentation marks commitment to hepatocyte death.

Canonical NAPQI-Mitochondrial Necrosis Model

hepatocyte CL:0000182

DNA catabolic process GO:0006308 ↑ INCREASED

mitochondrion GO:0005739 nucleus GO:0005634

Downstream

Centrilobular Oncotic Hepatocyte Necrosis Irreversible mitochondrial failure and nuclear DNA fragmentation culminate in oncotic hepatocyte necrosis.

Show evidence (2 references)

PMID:38265880 SUPPORT Other

"Mitochondria-derived endonucleases trigger nuclear DNA fragmentation, the point of no return for cell death."

The review defines this mitochondrial-to-nuclear commitment step.

PMID:22378043 SUPPORT Human Clinical

"Peak nuclear DNA fragmentation in the abnormal LT cohort was also increased over that of controls."

Patient plasma provides direct evidence of nuclear DNA fragmentation during human acetaminophen liver injury.

Centrilobular Oncotic Hepatocyte Necrosis

Irreversible mitochondrial injury produces predominantly oncotic necrosis in centrilobular hepatocytes. This is the central tissue lesion that releases aminotransferases and damage signals and reduces functional hepatic mass.

Canonical NAPQI-Mitochondrial Necrosis Model Sterile Inflammation Injury-Repair Context Model

hepatocyte CL:0000182

cell death GO:0008219 ↑ INCREASED

liver UBERON:0002107

Downstream

Sterile Inflammatory and Regenerative Response Necrotic hepatocytes release damage signals that activate innate immune cells involved in injury containment and repair.

Acetaminophen-Induced Acute Liver Injury and Failure Extensive hepatocyte loss reduces hepatic synthetic, metabolic, and detoxifying capacity and can culminate in acute liver failure.

Elevated hepatic transaminases Necrotic liver injury is accompanied by increased plasma aminotransferase activity.

Show evidence (2 references)

PMID:1214189 SUPPORT Human Clinical

"Confluent centrilobular necrosis of varying extent was followed by rapid disappearance of necrotic cells"

Biopsies from 104 patients directly establish the centrilobular necrotic lesion.

PMID:38265880 SUPPORT Other

"Extensive evidence supports oncotic necrosis as the mode of cell death"

The modern review supports oncotic necrosis as the predominant death mode.

Sterile Inflammatory and Regenerative Response

Damage-associated signals from necrotic hepatocytes activate Kupffer cells, monocyte-derived macrophages, and neutrophils. These cells can participate in inflammatory injury, clearance of necrotic debris, and regeneration; the evidence does not justify a universal net-amplification edge to liver failure.

Kupffer cell CL:0000091 macrophage CL:0000235 neutrophil CL:0000775

inflammatory response GO:0006954 ↑ INCREASED

Show evidence (2 references)

PMID:38265880 SUPPORT Other

"sterile inflammation in injury and repair with activation of Kupffer cells, monocyte-derived macrophages, and neutrophils"

The review supports the response while explicitly framing injury and repair roles.

PMID:35905941 SUPPORT Human Clinical

"the inflammatory response after APAP overdose in patients is not mediated by a second phase of inflammation driven by the inflammasome"

Longitudinal patient cytokine data argue against a simple second injurious inflammasome phase.

Acetaminophen-Induced Acute Liver Injury and Failure

Loss of functional hepatocyte mass first produces biochemical acute liver injury and, in severe cases, hepatic synthetic failure, impaired detoxification, encephalopathy, and multiorgan complications. Jaundice may occur but is not required to define acute liver failure.

Canonical NAPQI-Mitochondrial Necrosis Model

hepatocyte CL:0000182

liver UBERON:0002107

Downstream

Acute hepatic failure Severe injury crosses into loss of hepatic synthetic and detoxifying function.

Jaundice Severe loss of hepatic function may impair bilirubin handling and produce jaundice.

Prolonged prothrombin time Loss of hepatic clotting-factor synthesis prolongs prothrombin time and increases INR.

Hepatic encephalopathy Failure of hepatic detoxification and systemic metabolic disturbance produce hepatic encephalopathy.

Acute kidney injury Acetaminophen-induced acute liver failure can be complicated by acute kidney injury as part of systemic critical illness.

Shock Systemic inflammatory and circulatory failure can produce hypotension requiring vasopressor support.

Increased intracranial pressure Severe hepatic encephalopathy can progress through cerebral edema to intracranial hypertension.

Show evidence (2 references)

PMID:16317692 SUPPORT Human Clinical

"fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"

The multicenter cohort defines acute liver failure by coagulopathy and encephalopathy.

PMID:36001996 SUPPORT Other

"acetaminophen toxicity, which evolves so rapidly that delay is likely to lead to death"

The modern management review supports the hyperacute severity and need for early escalation.

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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

Referential integrity issues (1):

Source 'Centrilobular hepatocyte necrosis' (for edge to 'Elevated hepatic transaminases') not found in named elements

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Phenotypes

10

Cardiovascular 1

Shock HP:0031273

Show evidence (1 reference)

PMID:36001996 SUPPORT Other

"the systemic (extrahepatic) features of ALF (cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, sepsis)"

The modern review identifies cardiovascular collapse as an extrahepatic ALF consequence.

Digestive 3

Nausea and vomiting HP:0002017

Show evidence (1 reference)

PMID:6359859 SUPPORT Other

"Symptoms of nausea, vomiting, diaphoresis, and anorexia usually begin within seven to 14 hours after ingestion."

The clinical review directly identifies nausea and vomiting in the initial stage.

Acute hepatic failure HP:0006554

Show evidence (2 references)

PMID:16317692 SUPPORT Human Clinical

"fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"

The multicenter cohort applies standard acute liver failure criteria.

PMID:35615243 SUPPORT Other

"in a patient with no prior history of liver disease"

The clinical review directly supports exclusion of known preexisting liver disease from the acute-liver-failure definition.

Jaundice HP:0000952

Show evidence (2 references)

PMID:35615243 SUPPORT Other

"coagulopathy of liver origin, jaundice and encephalopathy in a patient with no prior history of liver disease"

The clinical review directly supports jaundice as a manifestation that can accompany paracetamol-related acute liver failure.

PMID:16317692 SUPPORT Human Clinical

"fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"

The multicenter cohort's standard criteria support the caveat that jaundice is not required to define acute liver failure.

Genitourinary 1

Acute kidney injury HP:0001919

Show evidence (1 reference)

PMID:36001996 SUPPORT Other

"cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, sepsis"

The modern ALF review lists acute kidney injury among systemic complications.

Metabolism 2

Elevated hepatic transaminases Elevated circulating hepatic transaminase concentration HP:0002910

Show evidence (1 reference)

PMID:28421844 SUPPORT Human Clinical

"Hepatotoxicity was defined as peak alanine aminotransferase ≥1000 IU/L"

The modified-release cohort uses marked ALT elevation to define hepatotoxicity.

Metabolic acidosis HP:0001942

Show evidence (1 reference)

PMID:25133498 SUPPORT Other

"early development of altered mental status and severe metabolic acidosis prior to the onset of hepatic failure"

EXTRIP documents the early mitochondrial-toxicity presentation.

Nervous System 2

Hepatic encephalopathy HP:0002480

Show evidence (1 reference)

PMID:16317692 SUPPORT Human Clinical

"fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"

The multicenter cohort identifies encephalopathy as a defining severe feature.

Increased intracranial pressure HP:0002516

Show evidence (1 reference)

PMID:32920216 SUPPORT Human Clinical

"less likely to develop intracranial hypertension (29.9% vs 51.5%; P < .001)"

The large APAP-ALF cohort directly documents the neurologic complication and its temporal decline.

Other 1

Prolonged prothrombin time HP:0008151

Show evidence (1 reference)

PMID:1214189 SUPPORT Human Clinical

"correlated well with the clinical course and both the maximal prolongation of the prothrombin time"

The biopsy cohort links loss of viable liver parenchyma to prolonged prothrombin time.

💊

Medical Actions

6

N-acetylcysteine

Category: Therapeutic Action: antidote agent therapy Ontology label: Pharmacotherapy NCIT:C15986

Agent: acetylcysteine NCIT:C200

N-acetylcysteine (NAC) is the established antidote. It is most protective when started early, but treatment remains beneficial when presentation is delayed or acute liver failure is established. Regimen selection and stopping require clinical assessment; no single intensified regimen or bedside stopping protocol is asserted here.

Mechanism Target:

INHIBITS NAPQI Formation, Protein Adduction, and Glutathione Depletion — NAC supplies cysteine for glutathione restoration and increases capacity to detoxify reactive metabolite.

Show evidence (1 reference)

PMID:24905542 SUPPORT In Vitro

"improved scavenging of the reactive metabolite NAPQI due to accelerated GSH synthesis"

The human-hepatocyte study directly states the early glutathione-dependent mechanism represented by this inhibitory edge.

Target Phenotypes: Acute hepatic failure HP:0006554

Show evidence (3 references)

PMID:3059186 SUPPORT Human Clinical

"When given within eight hours of acetaminophen ingestion, N-acetylcysteine was protective regardless of the initial plasma acetaminophen concentration."

The large multicenter study directly supports strong early clinical efficacy.

PMID:1954453 SUPPORT Human Clinical

"The rate of survival was significantly higher in the acetylcysteine treated group than in the controls"

The prospective controlled trial supports benefit after fulminant hepatic failure is established.

PMID:37552484 SUPPORT Other

"detailed management of acetylcysteine treatment, associated adverse effects, and stopping criteria"

The multisociety consensus confirms that treatment management and stopping require explicit criteria, without this entry asserting a bedside protocol.

Activated charcoal gastrointestinal decontamination

Category: Therapeutic Action: pharmacotherapy Ontology label: Pharmacotherapy NCIT:C15986

Agent: charcoal CHEBI:91090

Patients who present early after acute acetaminophen poisoning should be offered activated charcoal as gastrointestinal decontamination.

Show evidence (2 references)

PMID:34053705 SUPPORT Other

"Patients who present early should be offered activated charcoal"

The toxicology review directly supports early decontamination after acute exposure.

PMID:37552484 SUPPORT Other

"defining the role of gastrointestinal decontamination"

The consensus includes exposure-pattern-specific gastrointestinal decontamination guidance.

Intermittent hemodialysis for exceptional high-risk poisoning

Category: Therapeutic Action: hemodialysis Ontology label: Hemodialysis NCIT:C15248

Extracorporeal removal is not warranted in most acetaminophen poisonings because NAC is effective. Intermittent hemodialysis is a rare adjunct for exceptionally large exposure with early mitochondrial dysfunction such as altered consciousness and severe metabolic acidosis. The recommendation is based on very-low-quality evidence and accompanies, rather than replaces, antidotal care.

Mechanism Target:

INHIBITS Supratherapeutic Acetaminophen Exposure — Hemodialysis removes circulating acetaminophen during the exceptional early high-concentration state.

Show evidence (1 reference)

PMID:25133498 SUPPORT Other

"APAP is amenable to extracorporeal removal."

EXTRIP directly supports removal of circulating acetaminophen by extracorporeal treatment.

Target Phenotypes: Metabolic acidosis HP:0001942

Show evidence (2 references)

PMID:25133498 SUPPORT Other

"ECTR is not warranted in most cases of APAP poisoning"

The workgroup explicitly restricts extracorporeal treatment to exceptional cases.

PMID:25133498 SUPPORT Other

"yielding an overall very low quality of evidence for all recommendations"

The source directly calibrates the certainty of its recommendation.

Fomepizole as an investigational adjunct

Category: Therapeutic Action: antidote agent therapy Ontology label: Pharmacotherapy NCIT:C15986

Agent: fomepizole CHEBI:5141

Fomepizole inhibits CYP2E1 and JNK in mechanistic studies and has been used off label with NAC in selected high-risk cases. A small uncontrolled case series supports safety and feasibility, but a much larger comparative cohort found no clinical outcome benefit. Routine use is unsupported; any consideration belongs under specialist toxicology guidance.

Mechanism Target:

INHIBITS NAPQI Formation, Protein Adduction, and Glutathione Depletion — Proposed CYP2E1 inhibition could reduce additional NAPQI formation; this mechanistic rationale is not proof of clinical benefit.

Show evidence (1 reference)

PMID:34709101 SUPPORT Human Clinical

"is a potent CYP2E1 and c-Jun-N-terminal Kinase (JNK) inhibitor"

The prospective case series states the mechanistic rationale but cannot establish comparative efficacy.

Show evidence (3 references)

PMID:34709101 SUPPORT Human Clinical

"This case series has demonstrated the safety of fomepizole in high-risk APAP overdose."

Fourteen selected patients provide limited safety and feasibility evidence without a control group.

PMID:34709101 SUPPORT Human Clinical

"The efficacy of fomepizole needs to be further elucidated through controlled clinical trials on a larger scale."

The investigators explicitly acknowledge that efficacy is unresolved.

PMID:41886998 REFUTE Human Clinical

"Fomepizole as an adjunct to N-acetylcysteine in patients with high-risk acetaminophen overdose did not improve clinical outcomes"

The 391-patient comparative cohort directly refutes a claim of demonstrated routine outcome benefit.

Supportive critical care for acute liver failure

Category: Therapeutic Action: supportive care Ontology label: Supportive Care NCIT:C15747

Severe acute liver failure requires serial neurologic, metabolic, coagulation, renal, respiratory, and hemodynamic assessment with organ support as indicated, including cardiovascular, respiratory, and renal support and management of encephalopathy and cerebral edema.

Target Phenotypes: Hepatic encephalopathy HP:0002480 Acute kidney injury HP:0001919 Shock HP:0031273

Show evidence (1 reference)

PMID:36001996 SUPPORT Other

"Management involves optimizing fluid balance and cardiovascular support, including the use of continuous renal replacement therapy, vasopressors, and pulmonary ventilation."

The modern review supports multidisciplinary organ support in acute liver failure.

Early transplant-center evaluation and liver transplantation

Category: Therapeutic Action: liver transplantation Ontology label: Liver Transplantation NCIT:C15271

Progressive coagulopathy, encephalopathy, or multiorgan failure despite antidotal and critical care should trigger early transplant-center evaluation. Prognostic scores and serial trends inform multidisciplinary judgment but are imperfect; transplantation is a rescue option for patients judged unlikely to survive with medical therapy alone.

Target Phenotypes: Acute hepatic failure HP:0006554 Hepatic encephalopathy HP:0002480

Show evidence (2 references)

PMID:36001996 SUPPORT Other

"Early evaluation for liver transplantation is advised particularly for acetaminophen toxicity"

The modern ALF update supports early evaluation rather than waiting for irreversible deterioration.

PMID:36001996 SUPPORT Other

"provide reasonable but imperfect predictive accuracy"

The review calibrates prognostic scores as decision support rather than absolute rules.

🌍

Environmental Factors

4

Supratherapeutic acetaminophen exposure

Acute overdose or repeated supratherapeutic ingestion supplies the toxic substrate load. Intent may be deliberate or unintentional, and use of multiple acetaminophen-containing products can obscure cumulative exposure.

Show evidence (2 references)

PMID:36670547 SUPPORT Other

"is relatively safe at therapeutic doses; however, APAP overdose may lead to fatal acute liver injury"

The review distinguishes therapeutic exposure from hepatotoxic overdose.

PMID:16317692 SUPPORT Human Clinical

"Unintentional overdoses accounted for 131 (48%) cases, intentional (suicide attempts) 122 (44%)"

The cohort documents both unintentional and intentional exposure contexts.

Mechanism Target:

TRIGGERS Supratherapeutic Acetaminophen Exposure — An overdose or repeated supratherapeutic ingestion is what puts acetaminophen into the body above the dose safe conjugation can handle. The exposure event and the systemic state it produces are the same step, which is why the toxicity is dose-defined rather than intrinsic to the drug.

Show evidence (1 reference)

PMID:36670547 SUPPORT Other

"is relatively safe at therapeutic doses; however, APAP overdose may lead to fatal acute liver injury"

Distinguishes therapeutic dosing, which is safe, from overdose, which produces fatal acute liver injury, establishing the exposure as dose-defined.

Chronic alcohol use and CYP2E1-inducing comedications

Chronic alcohol use can transiently increase hepatic CYP2E1 content, and selected comedications such as antituberculosis and antiepileptic drugs can also favor CYP induction. These are susceptibility contexts rather than claims that a therapeutic acetaminophen dose is invariably hepatotoxic. Simultaneous acute alcohol ingestion has different metabolic effects and is not modeled here as equivalent to chronic alcohol use.

Show evidence (2 references)

PMID:12006215 SUPPORT Other

"chronic alcohol use leads to a short-term, two- to threefold increase in hepatic content of cytochrome P4502E1"

The review directly supports transient CYP2E1 induction after chronic alcohol use while distinguishing it from simultaneous alcohol ingestion.

PMID:36713231 SUPPORT Other

"some of them seem pivotal for the induction of cytochrome P450 2E1 (CYP2E1), which favors the conversion of APAP to the toxic metabolite"

The critical review identifies CYP2E1 induction as a shared mechanism through which susceptibility factors can increase NAPQI formation.

Mechanism Target:

EXACERBATES NAPQI Formation, Protein Adduction, and Glutathione Depletion — Induced CYP2E1 shunts more of a given acetaminophen dose down the oxidative route. This does not create the pathway, it increases flux through it, which is why it narrows the margin between exposure and hepatotoxicity.

Show evidence (1 reference)

PMID:36713231 SUPPORT Other

"some of them seem pivotal for the induction of cytochrome P450 2E1 (CYP2E1), which favors the conversion of APAP to the toxic metabolite"

Names CYP2E1 induction as favoring conversion of acetaminophen to its toxic metabolite, the reaction this node describes.

Malnutrition and eating disorders

Malnutrition, including malnutrition secondary to an eating disorder, can reduce intrahepatic glutathione available to detoxify NAPQI. Acute fasting alone is not treated as an equivalent risk factor because the focused evidence review did not associate it with increased risk through glutathione depletion.

Show evidence (2 references)

PMID:27147856 SUPPORT Other

"malnutrition, and eating disorders such as anorexia nervosa are likely to be associated with reduction in intrahepatic glutathione concentrations"

The review supports malnutrition-associated glutathione depletion as a susceptibility mechanism.

PMID:27147856 REFUTE Other

"Ageing and acute fasting are not associated with an increased risk of paracetamol-related hepatotoxicity due to reductions in glutathione concentrations."

This negative evidence prevents overgeneralizing malnutrition evidence to short-term fasting alone.

Mechanism Target:

EXACERBATES NAPQI Formation, Protein Adduction, and Glutathione Depletion — A lower baseline pool of intrahepatic glutathione means the same NAPQI load exhausts detoxification sooner, worsening the depletion arm of this node rather than creating it. The cited source specifically excludes ageing and acute fasting from this effect.

Show evidence (1 reference)

PMID:27147856 SUPPORT Other

"malnutrition, and eating disorders such as anorexia nervosa are likely to be associated with reduction in intrahepatic glutathione concentrations"

Associates malnutrition and eating disorders with reduced intrahepatic glutathione, the substrate whose depletion this node describes.

Obesity and nonalcoholic fatty liver disease

Retrospective hospitalized-overdose cohorts summarized in a critical review reported a four- to sevenfold higher prevalence of acute liver injury in people with pre-existing NAFLD. The association is heterogeneous: obesity and NAFLD can increase CYP2E1-dependent NAPQI formation in some metabolic contexts, while other metabolic changes can mitigate toxicity.

Show evidence (2 references)

PMID:36713231 SUPPORT Other

"could be more hepatotoxic in obesity and related metabolic diseases, at least after an overdose. Nonetheless, several investigations did not reproduce these data."

The review supports a clinically reported susceptibility association but explicitly documents inconsistent replication.

PMID:36713231 SUPPORT Other

"some of them seem pivotal for the induction of cytochrome P450 2E1 (CYP2E1), which favors the conversion of APAP to the toxic metabolite"

The review supports CYP2E1 induction and increased NAPQI formation as one mechanism that can raise susceptibility in obesity and NAFLD.

Mechanism Target:

PREDISPOSES Acetaminophen-Induced Acute Liver Injury and Failure — Reported as a higher prevalence of acute liver injury after overdose in people with pre-existing fatty liver disease, but the finding is inconsistent between studies and no mediating step is established. Modelled as PREDISPOSES rather than EXACERBATES because the evidence is a susceptibility association, not a demonstrated amplification of any particular mechanism.

Show evidence (1 reference)

PMID:36713231 SUPPORT Other

"could be more hepatotoxic in obesity and related metabolic diseases, at least after an overdose. Nonetheless, several investigations did not reproduce these data."

States both the reported increase in hepatotoxicity in obesity and related metabolic disease and the failure of several investigations to reproduce it, which is why this is recorded as a susceptibility association rather than a causal amplifier.

🔬

Biochemical Markers

5

Serum acetaminophen concentration (INCREASED)

Context: A timed serum concentration reports systemic exposure. Its interpretation is time-, formulation-, and ingestion-pattern dependent; a low or undetectable level in a late presenter does not exclude established hepatic injury.

Pathograph Readouts

Readout Of Supratherapeutic Acetaminophen Exposure Threshold Dependent Diagnostic

A properly timed concentration can quantify exposure risk only within an applicable acute-ingestion pathway.

Show evidence (1 reference)

PMID:34053705 SUPPORT Other

"The acetaminophen nomogram is used to assess the need for treatment in acute immediate-release overdoses with a known time of ingestion."

The review supplies the restricted context for interpreting the concentration.

Show evidence (2 references)

PMID:33778331 SUPPORT Human Clinical

"the acetaminophen concentration is low or undetectable at arrival to care"

The clinical report directly documents that a low or undetectable arrival concentration can coexist with acetaminophen-related acute liver failure.

PMID:37552484 SUPPORT Other

"A revised form of the Rumack-Matthew nomogram was developed."

The consensus includes time-dependent serum concentration interpretation in acute ingestion management.

Serum alanine and aspartate aminotransferases (INCREASED)

Context: Serial ALT and AST report hepatocyte injury and can rise after early symptoms improve. They do not by themselves measure hepatic function.

Pathograph Readouts

Correlates With Centrilobular Oncotic Hepatocyte Necrosis Positive Monitoring

Rising aminotransferases reflect increasing hepatocyte injury and membrane release.

Show evidence (1 reference)

PMID:28421844 SUPPORT Human Clinical

"Hepatotoxicity was defined as peak alanine aminotransferase ≥1000 IU/L"

The direct cohort links marked ALT elevation to hepatotoxicity.

Show evidence (1 reference)

PMID:37683599 SUPPORT Other

"maximum abnormalities of liver function were delayed for 3 days or more after an overdose"

The review supports delayed peak laboratory abnormalities and serial assessment.

International normalized ratio (INCREASED)

Context: Rising INR reflects hepatic synthetic failure rather than the magnitude of hepatocyte enzyme release and contributes to serial severity assessment.

Pathograph Readouts

Correlates With Acetaminophen-Induced Acute Liver Injury and Failure Positive Prognostic

Higher and worsening INR indicates loss of hepatic synthetic function and more severe disease.

Show evidence (1 reference)

PMID:1214189 SUPPORT Human Clinical

"correlated well with the clinical course and both the maximal prolongation of the prothrombin time"

Human biopsy data link loss of viable parenchyma to prothrombin-time prolongation.

Show evidence (1 reference)

PMID:16317692 SUPPORT Human Clinical

"fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"

The cohort supports coagulopathy as a defining functional-failure marker.

Serum acetaminophen-protein adducts (INCREASED)

Context: APAP-cysteine protein adducts report NAPQI-mediated protein binding and may help identify acetaminophen etiology when exposure history or the parent-drug concentration is unavailable. The assay is specialized rather than a routine bedside test.

Pathograph Readouts

Readout Of NAPQI Formation, Protein Adduction, and Glutathione Depletion Present Absent Diagnostic

Detectable serum adducts provide evidence of hepatic NAPQI-protein binding and hepatocyte lysis.

Show evidence (1 reference)

PMID:16530510 SUPPORT Human Clinical

"Acetaminophen-protein adducts were detected in serum in 100% of known acetaminophen ALF patients"

The multicenter study directly supports the diagnostic readout in known APAP-ALF.

Show evidence (1 reference)

PMID:19439490 SUPPORT Human Clinical

"Adducts were detected in some patient samples 12 days post-ingestion."

Human pharmacokinetic data support persistence beyond the parent-drug detection window.

Circulating CXCL14 (INCREASED)

Context: CXCL14 is a research-stage prognostic candidate in acetaminophen-induced acute liver failure. Discovery and independent-validation cohorts are promising, but external validation and routine clinical implementation are not established.

Pathograph Readouts

Predicts Acetaminophen-Induced Acute Liver Injury and Failure Positive Prognostic

Higher early CXCL14 was associated with death or transplantation in the studied cohorts; it is not an established transplant selector.

Show evidence (1 reference)

PMID:37910653 SUPPORT Human Clinical

"We find in 2 independent cohorts of acetaminophen overdose patients that circulating CXCL14 concentration is a novel early prognostic biomarker"

The primary study supplies discovery and independent validation evidence.

Show evidence (1 reference)

PMID:37910653 SUPPORT Human Clinical

"combining MELD and CXCL14 yielded the best AUC (0.860)"

The study supports incremental prognostic association while remaining a research-stage result.

🔬

Diagnosis

3

Timed serum acetaminophen concentration and nomogram assessment

A serum concentration obtained at an interpretable time can be plotted on the Rumack-Matthew nomogram for an acute immediate-release overdose with a known ingestion time. Modified-release, large, and repeated supratherapeutic ingestions require different assessment pathways.

blood chemistry measurement NCIT:C47868

Results: Time-dependent concentration interpretation identifies an acute-ingestion treatment-risk category; it does not independently diagnose established hepatic injury.

Show evidence (2 references)

PMID:34053705 SUPPORT Other

"The acetaminophen nomogram is used to assess the need for treatment in acute immediate-release overdoses with a known time of ingestion."

The toxicology review defines the core nomogram scope.

PMID:37552484 SUPPORT Other

"A revised form of the Rumack-Matthew nomogram was developed."

The multisociety consensus is the current North American framework for nomogram-based assessment.

Serial liver-injury and liver-failure assessment

Serial ALT and AST trends report hepatocellular injury, while bilirubin and PT or INR report evolving excretory and synthetic dysfunction. Coagulopathy together with encephalopathy identifies progression to acute liver failure.

clinical laboratory procedure NCIT:C25294

Markers: ALT, AST, bilirubin, PT/INR, and clinical encephalopathy assessment

Results: Rising aminotransferases indicate injury; worsening bilirubin or PT/INR and development of encephalopathy indicate functional progression.

Show evidence (2 references)

PMID:6359859 SUPPORT Other

"SGOT, SGPT, bilirubin, and prothrombin time begin to rise."

The clinical review directly identifies the serial laboratory abnormalities retained here.

PMID:16317692 SUPPORT Human Clinical

"fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"

The multicenter cohort directly supports the functional-failure assessment.

Serum acetaminophen-protein adduct analysis

Specialized serum APAP-protein adduct measurement can support an acetaminophen etiology in late or indeterminate acute liver failure when history is unavailable or the acetaminophen concentration is low or undetectable at arrival. It is an adjunct and is not assumed to be routinely available.

biomarker analysis NCIT:C63333

Results: Detectable APAP-protein adducts support NAPQI-mediated acetaminophen toxicity in the appropriate acute liver injury context.

Show evidence (4 references)

PMID:33778331 SUPPORT Human Clinical

"the acetaminophen concentration is low or undetectable at arrival to care"

The clinical report directly supports using adducts when the parent-drug concentration is no longer diagnostic.

PMID:33778331 SUPPORT Other

"APAP-protein adduct measurement by HPLC-EC or LC-MS/MS remains experimental and limited to research centers"

The report directly calibrates current assay availability and supports treating adduct testing as a specialized adjunct.

PMID:16530510 SUPPORT Human Clinical

"Measurement of serum acetaminophen-protein adducts reliably identified acetaminophen toxicity"

The prospective multicenter study directly supports etiologic diagnostic utility.

+ 1 more reference

📈

Progression

4

Initial nonspecific phase, usually within 24 hours

Nausea, vomiting, diaphoresis, and anorexia can begin during the initial post-ingestion stage. Exceptionally large exposures can instead produce early altered mental status and severe metabolic acidosis before hepatic failure develops.

Show evidence (2 references)

PMID:6359859 SUPPORT Other

"Symptoms of nausea, vomiting, diaphoresis, and anorexia usually begin within seven to 14 hours after ingestion."

The clinical review directly describes the initial symptom cluster and its timing.

PMID:25133498 SUPPORT Other

"early development of altered mental status and severe metabolic acidosis prior to the onset of hepatic failure"

EXTRIP identifies an important exceptional early mitochondrial-toxicity presentation after extremely large exposure.

Evolving hepatocellular injury, commonly 24 to 72 hours

Early symptoms may diminish while aminotransferases, bilirubin, and prothrombin time begin to rise. Peak biochemical injury can remain delayed for three days or more after overdose.

Show evidence (2 references)

PMID:6359859 SUPPORT Other

"After 24 to 48 hours, these symptoms may diminish, but SGOT, SGPT, bilirubin, and prothrombin time begin to rise."

The review directly describes symptom improvement accompanying emerging biochemical and synthetic dysfunction.

PMID:37683599 SUPPORT Other

"maximum abnormalities of liver function were delayed for 3 days or more after an overdose"

The historical review independently supports delayed peak laboratory injury.

Peak injury and possible acute liver failure, commonly 72 to 96 hours

Peak hepatotoxicity commonly occurs during this interval. Severe cases can cross into acute liver failure with coagulopathy and encephalopathy and can develop systemic complications such as cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, and sepsis.

Show evidence (3 references)

PMID:6359859 SUPPORT Other

"Peak hepatotoxicity occurs at 72 to 96 hours"

The clinical review directly supplies the commonly described peak-injury interval.

PMID:16317692 SUPPORT Human Clinical

"Severe acetaminophen hepatotoxicity frequently leads to acute liver failure"

The prospective cohort confirms acute liver failure as the severe trajectory.

PMID:36001996 SUPPORT Other

"cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, sepsis"

The acute-liver-failure review directly identifies the systemic complications retained in this phase.

Recovery or outcome after peak injury

Survivors can show substantial histologic recovery after severe injury. Severe cases may instead die or undergo liver transplantation; cohort percentages are contextual rather than individual prognostic guarantees.

Show evidence (2 references)

PMID:1214189 SUPPORT Human Clinical

"The histological recovery in even the most severe cases was remarkable"

The human biopsy series directly documents post-injury histologic recovery among survivors.

PMID:16317692 SUPPORT Human Clinical

"178 subjects (65%) survived, 74 (27%) died without transplantation, and 23 subjects (8%) underwent liver transplantation"

The multicenter cohort documents the range of severe outcomes.

🌍

Epidemiology

1

Acetaminophen contribution to United States acute liver failure

In a prospective cohort at 22 United States tertiary centers, acetaminophen injury accounted for 275 of 662 enrolled acute liver failure cases. This is a proportion within an acute-liver-failure referral cohort, not population prevalence of acetaminophen hepatotoxicity.

intentional overdose unintentional overdose use of multiple acetaminophen-containing preparations

Show evidence (1 reference)

PMID:16317692 SUPPORT Human Clinical

"275 (42%) were determined to result from acetaminophen liver injury"

The prospective study quantifies acetaminophen-attributed cases within its acute liver failure cohort.

🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Acetaminophen Hepatotoxicity:

Ischemic or hypoxic acute liver injury

Overlapping Features Ischemic injury and acetaminophen toxicity are both hyperacute causes of acute liver failure, so their clinical time courses can overlap.

Distinguishing Features

Acetaminophen-protein adducts were specific for acetaminophen-related acute liver failure against other defined causes in the cited cohort.

Show evidence (2 references)

PMID:36001996 SUPPORT Other

"Most causes of ALF can be divided into hyperacute (ischemia and acetaminophen) and subacute types"

The review directly places ischemia and acetaminophen in the overlapping hyperacute differential.

PMID:16530510 SUPPORT Human Clinical

"Acetaminophen-protein adducts were detected in serum in 100% of known acetaminophen ALF patients and in none of the ALF patients with other defined causes"

The prospective cohort directly supports adduct testing as a discriminator from other defined acute-liver-failure causes.

Fulminant viral hepatitis Not Yet Curated MONDO:0018109

Overlapping Features Viral etiologies are a distinct cause of acute liver failure and engage pathogen-associated immune signaling, whereas toxin-induced injury engages damage-associated signaling.

Distinguishing Features

The cited acute-liver-failure review distinguishes viral PAMP signaling from toxin-induced DAMP signaling.

Show evidence (1 reference)

PMID:36001996 SUPPORT Other

"Injuries by viral etiologies trigger the innate immune system via pathogen-associated molecular patterns (PAMPs), while toxin-induced (and presumably ischemia-induced) injuries do so via damage-associated molecular patterns (DAMPs)."

The ALF update directly distinguishes viral PAMP signaling from toxin-induced DAMP signaling.

Other drug-induced liver injury Not Yet Curated MONDO:0005359

Overlapping Features Other drug-related or defined causes can produce acute liver failure, but the cited prospective cohort found acetaminophen-protein adducts only in acetaminophen-related cases among its defined-cause comparison groups.

Distinguishing Features

Acetaminophen-protein adducts support acetaminophen toxicity over another defined acute-liver-failure cause in the cited cohort.

Show evidence (1 reference)

PMID:16530510 SUPPORT Human Clinical

"Acetaminophen-protein adducts were detected in serum in 100% of known acetaminophen ALF patients and in none of the ALF patients with other defined causes"

The prospective cohort directly supports adduct specificity against its other defined acute-liver-failure causes.

📊

Related Datasets

3

Dendritic cell iron overload exacerbates acetaminophen hepatotoxicity geo:GSE284273

Liver immune homeostasis relies on the coordinated actions of various immune cells including dendritic cells (DCs), which exert regulatory roles in both innate and adaptive immunity. Various pieces of evidence demonstrate that the properties of immune cells are highly influenced by iron metabolism. However, the roles of iron metabolism on DC function remain poorly understood. Here, we show that mice with iron overload in DCs displayed worsening of liver injury and mortality in acetaminophen (APAP) -induced acute hepatitis. Enhanced neutrophil infiltration was observed in these mice during the progression of liver injury.

mouse BULK RNA SEQ n=12

PMID:41120657

Identified by GEO DataSets index search for Acetaminophen Hepatotoxicity (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.

Hepatocyte-specific MET deletion exacerbates acetaminophen-induced hepatotoxicity in mice geo:GSE305543

Despite the well-known role of MET in liver regeneration following partial-hepatectomy (PHx), its role in the clinically-relevant acetaminophen (APAP)-induced liver injury (AILI) model remains unexplored. AILI markedly differs from PHx because it is associated with massive liver necrosis. This study aims to delineate the role of MET specifically in AILI. Hepatocyte-specific MET-KO mice were given a toxic-dose of APAP and assessed for hepatotoxicity/regeneration parameters. MET deletion strikingly exacerbated initial hepatotoxicity and impaired subsequent proliferative response, culminating in significant mortality.

mouse BULK RNA SEQ n=18

PMID:41038273

Identified by GEO DataSets index search for Acetaminophen Hepatotoxicity (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.

Raw data for manuscript : "Serine synthesis via reversed SHMT2 activity drives glycine depletion and acetaminophen hepatotoxicity in MASLD" massive:MSV000093653

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects one third of the global population. Understanding metabolic pathways involved can provide insights into disease progression and treatment. Untargeted metabolomics of livers from mice with early-stage steatosis uncovered decreased methylated metabolites, suggesting altered one-carbon metabolism. The levels of glycine, a central component of one-carbon metabolism, were lower in mice with hepatic steatosis, consistent with clinical evidence.

Located via OmicsDI, which aggregates across omics repositories; this record comes from massive. Only repositories with no other discovery route in this project and with a working accession resolver are curated from OmicsDI -- GEO, ArrayExpress, PRIDE, MetaboLights and EGA hits are excluded as duplicates of dedicated passes. Matched because the disease is named in the dataset's own title ("Acetaminophen Hepatotoxicity"). Retrieved 2026-08-02.

{ }

Source YAML

click to show

name: Acetaminophen Hepatotoxicity
creation_date: "2026-06-24T00:00:00Z"
category: Environmental
categories:
- Toxic Exposure Disorder
- Intrinsic Drug-Induced Liver Injury
- Hepatic Toxicity
description: >-
  Acetaminophen (paracetamol, APAP) hepatotoxicity is an intrinsic,
  dose-dependent liver injury caused by acute overdose or repeated
  supratherapeutic ingestion. Excess formation of the reactive metabolite
  N-acetyl-p-benzoquinone imine (NAPQI) depletes glutathione, forms protein
  adducts, and initiates mitochondrial oxidant stress. Mitochondrial
  permeability transition and nuclear DNA fragmentation culminate in
  centrilobular oncotic hepatocyte necrosis. Injury ranges from biochemical
  aminotransferase elevation to acute liver failure with coagulopathy,
  encephalopathy, multiorgan dysfunction, death, or transplantation. This entry
  models hepatotoxic injury rather than every acetaminophen exposure or every
  acetaminophen-poisoning presentation.
disease_term:
  preferred_term: acetaminophen hepatotoxicity
  term:
    id: MONDO:0018741
    label: paracetamol poisoning
synonyms:
- acetaminophen-induced liver injury
- acetaminophen-induced acute liver injury
- paracetamol hepatotoxicity
- paracetamol-induced liver injury
- APAP hepatotoxicity
parents:
- poisoning
- drug-induced liver injury
notes: >-
  MONDO:0018741 is broader than this hepatotoxicity-focused record because
  acetaminophen poisoning can be recognized before liver injury and can include
  nonhepatic manifestations. Intentional overdose, unintentional overdose, and
  repeated supratherapeutic ingestion are in scope when they cause or place the
  patient at material risk of hepatic injury. Therapeutic use without
  hepatotoxicity is out of scope.
classifications:
  harrisons_chapter:
  - classification_value: POISONING_ENVENOMATION
    evidence:
    - reference: PMID:37552484
      reference_title: "Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "The panel developed guidelines for emergency department management of single or repeated ingestion of acetaminophen."
      explanation: >-
        The multisociety consensus treats the condition as a poisoning and
        overdose-management problem, supporting its primary Harrison's
        placement.
  - classification_value: GASTROINTESTINAL
    evidence:
    - reference: PMID:35615243
      reference_title: Acute liver failure following paracetamol overdose.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Paracetamol overdose is the leading cause of acute liver failure in the United Kingdom"
      explanation: The severe clinical endpoint is hepatic failure, supporting a secondary hepatology placement.
mappings:
  mondo_mappings:
  - term:
      id: MONDO:0018741
      label: paracetamol poisoning
    mapping_predicate: skos:closeMatch
    mapping_source: MONDO
    mapping_justification: >-
      MONDO:0018741 is the closest chemical-specific concept, but it includes
      poisoning presentations without established hepatotoxicity.
  - term:
      id: MONDO:0005359
      label: drug-induced liver injury
    mapping_predicate: skos:broadMatch
    mapping_source: MONDO
    mapping_justification: >-
      Acetaminophen hepatotoxicity is the intrinsic, dose-dependent subtype of
      the broader drug-induced liver injury concept.
definitions:
- name: Hepatotoxicity-focused clinical scope
  definition_type: CASE_DEFINITION
  description: >-
    Acetaminophen hepatotoxicity is acute hepatocellular injury attributable to
    a toxic acetaminophen exposure, arising after an acute ingestion or repeated
    supratherapeutic use and ranging from aminotransferase elevation to acute
    liver failure. A detectable exposure without liver injury is not by itself
    the disease state modeled here.
  scope: Disease-level clinical framing for intrinsic acetaminophen liver injury
  evidence:
  - reference: PMID:36670547
    reference_title: The molecular mechanisms of acetaminophen-induced hepatotoxicity and its potential therapeutic targets.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "APAP overdose may lead to fatal acute liver injury."
    explanation: The review directly links overdose to the hepatic injury defining this record.
  - reference: PMID:37552484
    reference_title: "Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "single or repeated ingestion of acetaminophen"
    explanation: The consensus establishes both acute and repeated-ingestion exposure patterns as clinically relevant.
has_subtypes:
- name: Acute immediate-release ingestion within 24 hours
  description: >-
    An acute ingestion can include one or more doses presenting within 24 hours
    of the initial ingestion. For an immediate-release exposure with a known
    start time, a properly timed serum concentration can be interpreted with the
    Rumack-Matthew nomogram.
  evidence:
  - reference: PMID:40047505
    reference_title: "Out-of-hospital assessment and triage of paracetamol (acetaminophen) exposure in the United States and Canada: a consensus guideline."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Acute ingestion is defined as any ingestion presenting within 24 h of initial ingestion, regardless of ingestion pattern."
    explanation: The consensus definition prevents multiple doses within the first 24 hours from being misclassified as repeated supratherapeutic ingestion.
  - reference: PMID:34053705
    reference_title: Acetaminophen Poisoning.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The acetaminophen nomogram is used to assess the need for treatment in acute immediate-release overdoses with a known time of ingestion."
    explanation: The review defines the acute immediate-release scenario in which nomogram interpretation is appropriate.
- name: Modified-release acute ingestion
  description: >-
    Acute ingestion of a modified- or extended-release formulation can produce
    delayed absorption and requires a different assessment pathway from a
    conventional immediate-release ingestion.
  evidence:
  - reference: PMID:34053705
    reference_title: Acetaminophen Poisoning.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "scenarios that require different management pathways include modified-release"
    explanation: The review explicitly separates modified-release exposure from the standard nomogram pathway.
  - reference: PMID:28421844
    reference_title: Accuracy of the paracetamol-aminotransferase multiplication product to predict hepatotoxicity in modified-release paracetamol overdose.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "we identified 73 modified-release paracetamol exposures treated with acetylcysteine"
    explanation: A human cohort documents the modified-release exposure pattern and liver-injury follow-up.
- name: Repeated supratherapeutic ingestion
  description: >-
    Excess acetaminophen accumulated over an exposure period of 24 hours or
    more. This is distinct from an acute ingestion presenting within 24 hours of
    its start and requires a separate assessment pathway.
  evidence:
  - reference: PMID:40047505
    reference_title: "Out-of-hospital assessment and triage of paracetamol (acetaminophen) exposure in the United States and Canada: a consensus guideline."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Repeated supratherapeutic ingestion is defined as an exposure that occurs over a period of 24 h or more."
    explanation: The consensus directly defines the duration separating repeated supratherapeutic from acute ingestion.
  - reference: PMID:37552484
    reference_title: "Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The panel developed guidelines for emergency department management of single or repeated ingestion of acetaminophen."
    explanation: The consensus treats repeated ingestion as a distinct clinical assessment pathway.
epidemiology:
- name: Acetaminophen contribution to United States acute liver failure
  description: >-
    In a prospective cohort at 22 United States tertiary centers, acetaminophen
    injury accounted for 275 of 662 enrolled acute liver failure cases. This is
    a proportion within an acute-liver-failure referral cohort, not population
    prevalence of acetaminophen hepatotoxicity.
  unit: proportion of an acute liver failure cohort
  factors:
  - intentional overdose
  - unintentional overdose
  - use of multiple acetaminophen-containing preparations
  evidence:
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "275 (42%) were determined to result from acetaminophen liver injury"
    explanation: The prospective study quantifies acetaminophen-attributed cases within its acute liver failure cohort.
progression:
- phase: Initial nonspecific phase, usually within 24 hours
  notes: >-
    Nausea, vomiting, diaphoresis, and anorexia can begin during the initial
    post-ingestion stage. Exceptionally large exposures can instead produce
    early altered mental status and severe metabolic acidosis before hepatic
    failure develops.
  evidence:
  - reference: PMID:6359859
    reference_title: Acetaminophen overdose.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Symptoms of nausea, vomiting, diaphoresis, and anorexia usually begin within seven to 14 hours after ingestion."
    explanation: The clinical review directly describes the initial symptom cluster and its timing.
  - reference: PMID:25133498
    reference_title: "Extracorporeal treatment for acetaminophen poisoning: recommendations from the EXTRIP workgroup."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "early development of altered mental status and severe metabolic acidosis prior to the onset of hepatic failure"
    explanation: EXTRIP identifies an important exceptional early mitochondrial-toxicity presentation after extremely large exposure.
- phase: Evolving hepatocellular injury, commonly 24 to 72 hours
  notes: >-
    Early symptoms may diminish while aminotransferases, bilirubin, and
    prothrombin time begin to rise. Peak biochemical injury can remain delayed
    for three days or more after overdose.
  evidence:
  - reference: PMID:6359859
    reference_title: Acetaminophen overdose.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "After 24 to 48 hours, these symptoms may diminish, but SGOT, SGPT, bilirubin, and prothrombin time begin to rise."
    explanation: The review directly describes symptom improvement accompanying emerging biochemical and synthetic dysfunction.
  - reference: PMID:37683599
    reference_title: "Paracetamol (acetaminophen) poisoning: The early years."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "maximum abnormalities of liver function were delayed for 3 days or more after an overdose"
    explanation: The historical review independently supports delayed peak laboratory injury.
- phase: Peak injury and possible acute liver failure, commonly 72 to 96 hours
  notes: >-
    Peak hepatotoxicity commonly occurs during this interval. Severe cases can
    cross into acute liver failure with coagulopathy and encephalopathy and can
    develop systemic complications such as cardiovascular collapse, cerebral
    edema, acute kidney injury, respiratory failure, and sepsis.
  evidence:
  - reference: PMID:6359859
    reference_title: Acetaminophen overdose.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Peak hepatotoxicity occurs at 72 to 96 hours"
    explanation: The clinical review directly supplies the commonly described peak-injury interval.
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Severe acetaminophen hepatotoxicity frequently leads to acute liver failure"
    explanation: The prospective cohort confirms acute liver failure as the severe trajectory.
  - reference: PMID:36001996
    reference_title: "Management of Acute Liver Failure: Update 2022."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, sepsis"
    explanation: The acute-liver-failure review directly identifies the systemic complications retained in this phase.
- phase: Recovery or outcome after peak injury
  notes: >-
    Survivors can show substantial histologic recovery after severe injury.
    Severe cases may instead die or undergo liver transplantation; cohort
    percentages are contextual rather than individual prognostic guarantees.
  evidence:
  - reference: PMID:1214189
    reference_title: "Histopathological changes in the liver following a paracetamol overdose: correlation with clinical and biochemical parameters."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The histological recovery in even the most severe cases was remarkable"
    explanation: The human biopsy series directly documents post-injury histologic recovery among survivors.
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "178 subjects (65%) survived, 74 (27%) died without transplantation, and 23 subjects (8%) underwent liver transplantation"
    explanation: The multicenter cohort documents the range of severe outcomes.
mechanistic_hypotheses:
- hypothesis_group_id: canonical_napqi_mitochondrial_necrosis_model
  hypothesis_label: Canonical NAPQI-Mitochondrial Necrosis Model
  status: CANONICAL
  description: >-
    Supratherapeutic acetaminophen increases NAPQI formation beyond glutathione
    detoxification capacity. Glutathione depletion and mitochondrial protein
    adduction initiate mitochondrial oxidant and peroxynitrite stress with JNK
    amplification. Mitochondrial permeability transition and release of
    endonucleases cause nuclear DNA fragmentation and centrilobular oncotic
    hepatocyte necrosis, which can progress to acute liver failure.
  evidence:
  - reference: PMID:36670547
    reference_title: The molecular mechanisms of acetaminophen-induced hepatotoxicity and its potential therapeutic targets.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "APAP-induced hepatotoxicity (AIH) is mainly caused by the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI),"
    explanation: The review identifies NAPQI as the proximal toxic metabolite.
  - reference: PMID:38265880
    reference_title: "Acetaminophen Hepatotoxicity: Paradigm for Understanding Mechanisms of Drug-Induced Liver Injury."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Mitochondria-derived endonucleases trigger nuclear DNA fragmentation, the point of no return for cell death."
    explanation: The review supplies the mitochondrial-to-necrosis commitment step.
- hypothesis_group_id: sterile_inflammation_injury_repair_model
  hypothesis_label: Sterile Inflammation Injury-Repair Context Model
  status: ALTERNATIVE
  description: >-
    Necrotic hepatocytes release damage signals that activate Kupffer cells,
    monocyte-derived macrophages, and neutrophils. This response is established,
    but its net role is context-dependent: inflammatory signaling can accompany
    injury while immune cells also participate in debris clearance and repair.
    The graph therefore does not encode sterile inflammation as an invariably
    injurious linear amplifier.
  evidence:
  - reference: PMID:38265880
    reference_title: "Acetaminophen Hepatotoxicity: Paradigm for Understanding Mechanisms of Drug-Induced Liver Injury."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "sterile inflammation in injury and repair with activation of Kupffer cells, monocyte-derived macrophages, and neutrophils"
    explanation: The review explicitly frames the response as participating in both injury and repair.
  - reference: PMID:35024303
    reference_title: Recommendations for the use of the acetaminophen hepatotoxicity model for mechanistic studies and how to avoid common pitfalls.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "the critical roles of drug metabolism, mitochondrial dysfunction, necrotic cell death, autophagy and the sterile inflammatory response"
    explanation: The model review supports biological relevance while warning that interpretation requires care.
environmental:
- name: Supratherapeutic acetaminophen exposure
  influences_mechanisms:
  - target: Supratherapeutic Acetaminophen Exposure
    environmental_effect: TRIGGERS
    causal_link_type: DIRECT
    description: >-
      An overdose or repeated supratherapeutic ingestion is what puts
      acetaminophen into the body above the dose safe conjugation can handle.
      The exposure event and the systemic state it produces are the same step,
      which is why the toxicity is dose-defined rather than intrinsic to the
      drug.
    evidence:
    - reference: PMID:36670547
      reference_title: "The molecular mechanisms of acetaminophen-induced hepatotoxicity and its potential therapeutic targets."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "is relatively safe at therapeutic doses; however, APAP overdose may lead to fatal acute liver injury"
      explanation: >-
        Distinguishes therapeutic dosing, which is safe, from overdose, which
        produces fatal acute liver injury, establishing the exposure as
        dose-defined.
  description: >-
    Acute overdose or repeated supratherapeutic ingestion supplies the toxic
    substrate load. Intent may be deliberate or unintentional, and use of
    multiple acetaminophen-containing products can obscure cumulative exposure.
  presence: PRESENT
  chemicals:
  - acetaminophen
  - paracetamol
  exposure_term:
    preferred_term: exposure to paracetamol
    term:
      id: ECTO:9000387
      label: exposure to paracetamol
  effect: Initiates dose-dependent intrinsic hepatocellular injury when detoxification capacity is exceeded.
  evidence:
  - reference: PMID:36670547
    reference_title: The molecular mechanisms of acetaminophen-induced hepatotoxicity and its potential therapeutic targets.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "is relatively safe at therapeutic doses; however, APAP overdose may lead to fatal acute liver injury"
    explanation: The review distinguishes therapeutic exposure from hepatotoxic overdose.
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Unintentional overdoses accounted for 131 (48%) cases, intentional (suicide attempts) 122 (44%)"
    explanation: The cohort documents both unintentional and intentional exposure contexts.
- name: Chronic alcohol use and CYP2E1-inducing comedications
  influences_mechanisms:
  - target: NAPQI Formation, Protein Adduction, and Glutathione Depletion
    environmental_effect: EXACERBATES
    causal_link_type: DIRECT
    description: >-
      Induced CYP2E1 shunts more of a given acetaminophen dose down the
      oxidative route. This does not create the pathway, it increases flux
      through it, which is why it narrows the margin between exposure and
      hepatotoxicity.
    evidence:
    - reference: PMID:36713231
      reference_title: "Acetaminophen-Induced Hepatotoxicity in Obesity and Nonalcoholic Fatty Liver Disease: A Critical Review."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "some of them seem pivotal for the induction of cytochrome P450 2E1 (CYP2E1), which favors the conversion of APAP to the toxic metabolite"
      explanation: >-
        Names CYP2E1 induction as favoring conversion of acetaminophen to its
        toxic metabolite, the reaction this node describes.
  description: >-
    Chronic alcohol use can transiently increase hepatic CYP2E1 content, and
    selected comedications such as antituberculosis and antiepileptic drugs can
    also favor CYP induction. These are susceptibility contexts rather than
    claims that a therapeutic acetaminophen dose is invariably hepatotoxic.
    Simultaneous acute alcohol ingestion has different metabolic effects and is
    not modeled here as equivalent to chronic alcohol use.
  presence: PRESENT
  effect: Can increase bioactivation of acetaminophen to NAPQI and thereby lower the margin between exposure and hepatotoxicity.
  evidence:
  - reference: PMID:12006215
    reference_title: Alcohol exposure and paracetamol-induced hepatotoxicity.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "chronic alcohol use leads to a short-term, two- to threefold increase in hepatic content of cytochrome P4502E1"
    explanation: The review directly supports transient CYP2E1 induction after chronic alcohol use while distinguishing it from simultaneous alcohol ingestion.
  - reference: PMID:36713231
    reference_title: "Acetaminophen-Induced Hepatotoxicity in Obesity and Nonalcoholic Fatty Liver Disease: A Critical Review."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "some of them seem pivotal for the induction of cytochrome P450 2E1 (CYP2E1), which favors the conversion of APAP to the toxic metabolite"
    explanation: The critical review identifies CYP2E1 induction as a shared mechanism through which susceptibility factors can increase NAPQI formation.
- name: Malnutrition and eating disorders
  influences_mechanisms:
  - target: NAPQI Formation, Protein Adduction, and Glutathione Depletion
    environmental_effect: EXACERBATES
    causal_link_type: DIRECT
    description: >-
      A lower baseline pool of intrahepatic glutathione means the same NAPQI
      load exhausts detoxification sooner, worsening the depletion arm of this
      node rather than creating it. The cited source specifically excludes
      ageing and acute fasting from this effect.
    evidence:
    - reference: PMID:27147856
      reference_title: "A review of the evidence concerning hepatic glutathione depletion and susceptibility to hepatotoxicity after paracetamol overdose."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "malnutrition, and eating disorders such as anorexia nervosa are likely to be associated with reduction in intrahepatic glutathione concentrations"
      explanation: >-
        Associates malnutrition and eating disorders with reduced intrahepatic
        glutathione, the substrate whose depletion this node describes.
  description: >-
    Malnutrition, including malnutrition secondary to an eating disorder, can
    reduce intrahepatic glutathione available to detoxify NAPQI. Acute fasting
    alone is not treated as an equivalent risk factor because the focused
    evidence review did not associate it with increased risk through glutathione
    depletion.
  presence: PRESENT
  effect: Can reduce glutathione-dependent NAPQI detoxification and increase susceptibility after acetaminophen overdose.
  evidence:
  - reference: PMID:27147856
    reference_title: A review of the evidence concerning hepatic glutathione depletion and susceptibility to hepatotoxicity after paracetamol overdose.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "malnutrition, and eating disorders such as anorexia nervosa are likely to be associated with reduction in intrahepatic glutathione concentrations"
    explanation: The review supports malnutrition-associated glutathione depletion as a susceptibility mechanism.
  - reference: PMID:27147856
    reference_title: A review of the evidence concerning hepatic glutathione depletion and susceptibility to hepatotoxicity after paracetamol overdose.
    supports: REFUTE
    evidence_source: OTHER
    snippet: "Ageing and acute fasting are not associated with an increased risk of paracetamol-related hepatotoxicity due to reductions in glutathione concentrations."
    explanation: This negative evidence prevents overgeneralizing malnutrition evidence to short-term fasting alone.
- name: Obesity and nonalcoholic fatty liver disease
  influences_mechanisms:
  - target: Acetaminophen-Induced Acute Liver Injury and Failure
    environmental_effect: PREDISPOSES
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Reported as a higher prevalence of acute liver injury after overdose in
      people with pre-existing fatty liver disease, but the finding is
      inconsistent between studies and no mediating step is established.
      Modelled as PREDISPOSES rather than EXACERBATES because the evidence is
      a susceptibility association, not a demonstrated amplification of any
      particular mechanism.
    evidence:
    - reference: PMID:36713231
      reference_title: "Acetaminophen-Induced Hepatotoxicity in Obesity and Nonalcoholic Fatty Liver Disease: A Critical Review."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "could be more hepatotoxic in obesity and related metabolic diseases, at least after an overdose. Nonetheless, several investigations did not reproduce these data."
      explanation: >-
        States both the reported increase in hepatotoxicity in obesity and
        related metabolic disease and the failure of several investigations to
        reproduce it, which is why this is recorded as a susceptibility
        association rather than a causal amplifier.
  description: >-
    Retrospective hospitalized-overdose cohorts summarized in a critical review
    reported a four- to sevenfold higher prevalence of acute liver injury in
    people with pre-existing NAFLD. The association is heterogeneous: obesity
    and NAFLD can increase CYP2E1-dependent NAPQI formation in some metabolic
    contexts, while other metabolic changes can mitigate toxicity.
  presence: PRESENT
  effect: May increase susceptibility to acute liver injury after acetaminophen overdose, depending on the balance of metabolic factors.
  evidence:
  - reference: PMID:36713231
    reference_title: "Acetaminophen-Induced Hepatotoxicity in Obesity and Nonalcoholic Fatty Liver Disease: A Critical Review."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "could be more hepatotoxic in obesity and related metabolic diseases, at least after an overdose. Nonetheless, several investigations did not reproduce these data."
    explanation: The review supports a clinically reported susceptibility association but explicitly documents inconsistent replication.
  - reference: PMID:36713231
    reference_title: "Acetaminophen-Induced Hepatotoxicity in Obesity and Nonalcoholic Fatty Liver Disease: A Critical Review."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "some of them seem pivotal for the induction of cytochrome P450 2E1 (CYP2E1), which favors the conversion of APAP to the toxic metabolite"
    explanation: The review supports CYP2E1 induction and increased NAPQI formation as one mechanism that can raise susceptibility in obesity and NAFLD.
pathophysiology:
- name: Supratherapeutic Acetaminophen Exposure
  description: >-
    Acute overdose or repeated supratherapeutic ingestion exceeds safe
    conjugative handling and supplies acetaminophen for increased oxidative
    metabolism.
  role: trigger
  chemical_entities:
  - preferred_term: paracetamol
    term:
      id: CHEBI:46195
      label: paracetamol
  evidence:
  - reference: PMID:36670547
    reference_title: The molecular mechanisms of acetaminophen-induced hepatotoxicity and its potential therapeutic targets.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "APAP overdose may lead to fatal acute liver injury."
    explanation: The review identifies overdose as the initiating exposure.
  downstream:
  - target: NAPQI Formation, Protein Adduction, and Glutathione Depletion
    causal_link_type: DIRECT
    description: Excess acetaminophen increases formation of NAPQI beyond glutathione detoxification capacity.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:24905542
      reference_title: Mechanisms of acetaminophen-induced cell death in primary human hepatocytes.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "cellular glutathione was depleted rapidly during the first 3h"
      explanation: Primary human hepatocytes directly demonstrate early glutathione depletion after acetaminophen exposure.
  - target: Nausea and vomiting
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: Acute toxic exposure can produce nonspecific nausea and vomiting before liver injury is clinically apparent.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:6359859
      reference_title: Acetaminophen overdose.
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Symptoms of nausea, vomiting, diaphoresis, and anorexia usually begin within seven to 14 hours after ingestion."
      explanation: The clinical review directly places nausea and vomiting in the initial post-ingestion stage.
- name: NAPQI Formation, Protein Adduction, and Glutathione Depletion
  conforms_to: "drug_induced_liver_injury#Reactive Drug Metabolite Formation and Hepatocellular Stress"
  description: >-
    CYP2E1-mediated oxidative metabolism generates NAPQI. When
    glutathione-dependent detoxification is overwhelmed, NAPQI depletes
    glutathione and forms protein adducts, including adducts on mitochondrial
    proteins.
  role: proximal toxic mechanism
  genes:
  - preferred_term: CYP2E1
    term:
      id: hgnc:2631
      label: CYP2E1
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  locations:
  - preferred_term: liver
    term:
      id: UBERON:0002107
      label: liver
  chemical_entities:
  - preferred_term: N-acetyl-p-benzoquinone imine
    term:
      id: CHEBI:29132
      label: N-acetyl-1,4-benzoquinone imine
  - preferred_term: glutathione
    term:
      id: CHEBI:16856
      label: glutathione
  biological_processes:
  - preferred_term: xenobiotic metabolic process
    term:
      id: GO:0006805
      label: xenobiotic metabolic process
    modifier: INCREASED
  evidence:
  - reference: PMID:36670547
    reference_title: The molecular mechanisms of acetaminophen-induced hepatotoxicity and its potential therapeutic targets.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "APAP-induced hepatotoxicity (AIH) is mainly caused by the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI),"
    explanation: The review establishes NAPQI as the proximal toxic metabolite.
  - reference: PMID:24905542
    reference_title: Mechanisms of acetaminophen-induced cell death in primary human hepatocytes.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria)"
    explanation: Primary human hepatocytes directly demonstrate cellular and mitochondrial protein adduction.
  downstream:
  - target: Mitochondrial Oxidant Stress and JNK Amplification
    causal_link_type: DIRECT
    description: Mitochondrial protein adduction and glutathione loss initiate oxidant stress and a self-amplifying mitochondrial injury program.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:24905542
      reference_title: Mechanisms of acetaminophen-induced cell death in primary human hepatocytes.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "mitochondrial dysfunction, indicated by the loss of mitochondrial membrane potential"
      explanation: Human hepatocytes directly link protein adduction to mitochondrial dysfunction.
- name: Mitochondrial Oxidant Stress and JNK Amplification
  conforms_to: "drug_induced_liver_injury#Mitochondrial Dysfunction and Oxidative Stress"
  description: >-
    Mitochondrial adduct stress promotes superoxide and peroxynitrite formation.
    Stress-kinase signaling, including JNK translocation to mitochondria,
    amplifies the oxidant burden and impairs mitochondrial respiration. JNK
    evidence is strongest in experimental human hepatocytes and preclinical
    systems rather than controlled in-vivo human perturbation.
  role: amplifier
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  cellular_components:
  - preferred_term: mitochondrion
    term:
      id: GO:0005739
      label: mitochondrion
  biological_processes:
  - preferred_term: response to oxidative stress
    term:
      id: GO:0006979
      label: response to oxidative stress
    modifier: INCREASED
  evidence:
  - reference: PMID:36670547
    reference_title: The molecular mechanisms of acetaminophen-induced hepatotoxicity and its potential therapeutic targets.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Mitochondrial oxidative stress and dysfunction are the major cellular events associated with APAP-induced liver injury."
    explanation: The review identifies this mitochondrial program as a central event.
  - reference: PMID:22378043
    reference_title: The mechanism underlying acetaminophen-induced hepatotoxicity in humans and mice involves mitochondrial damage and nuclear DNA fragmentation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Peak GDH activity and mtDNA concentration were increased in plasma from patients with abnormal LT."
    explanation: Human overdose samples provide direct biomarker evidence of mitochondrial damage in patients with liver injury.
  - reference: PMID:24905542
    reference_title: Mechanisms of acetaminophen-induced cell death in primary human hepatocytes.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria"
    explanation: Primary human hepatocytes support the JNK amplification step.
  downstream:
  - target: Mitochondrial Permeability Transition and Nuclear DNA Fragmentation
    causal_link_type: DIRECT
    description: Sustained mitochondrial stress promotes organelle failure and release of endonucleases that fragment nuclear DNA.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:22378043
      reference_title: The mechanism underlying acetaminophen-induced hepatotoxicity in humans and mice involves mitochondrial damage and nuclear DNA fragmentation.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "mitochondrial damage and nuclear DNA fragmentation are likely to be critical events in APAP hepatotoxicity in humans"
      explanation: Direct human-overdose data support the linked mitochondrial and nuclear events.
  - target: Metabolic acidosis
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: In exceptionally large overdoses, early mitochondrial dysfunction can produce severe metabolic and lactic acidosis before hepatic failure.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:25133498
      reference_title: "Extracorporeal treatment for acetaminophen poisoning: recommendations from the EXTRIP workgroup."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "early development of altered mental status and severe metabolic acidosis prior to the onset of hepatic failure"
      explanation: EXTRIP recognizes early acidosis as a feature of mitochondrial dysfunction in exceptionally large overdoses.
- name: Mitochondrial Permeability Transition and Nuclear DNA Fragmentation
  description: >-
    Oxidant-driven permeability transition collapses mitochondrial function and
    permits mitochondria-derived endonucleases to reach the nucleus, where DNA
    fragmentation marks commitment to hepatocyte death.
  role: commitment step
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  cellular_components:
  - preferred_term: mitochondrion
    term:
      id: GO:0005739
      label: mitochondrion
  - preferred_term: nucleus
    term:
      id: GO:0005634
      label: nucleus
  biological_processes:
  - preferred_term: DNA catabolic process
    term:
      id: GO:0006308
      label: DNA catabolic process
    modifier: INCREASED
  evidence:
  - reference: PMID:38265880
    reference_title: "Acetaminophen Hepatotoxicity: Paradigm for Understanding Mechanisms of Drug-Induced Liver Injury."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Mitochondria-derived endonucleases trigger nuclear DNA fragmentation, the point of no return for cell death."
    explanation: The review defines this mitochondrial-to-nuclear commitment step.
  - reference: PMID:22378043
    reference_title: The mechanism underlying acetaminophen-induced hepatotoxicity in humans and mice involves mitochondrial damage and nuclear DNA fragmentation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Peak nuclear DNA fragmentation in the abnormal LT cohort was also increased over that of controls."
    explanation: Patient plasma provides direct evidence of nuclear DNA fragmentation during human acetaminophen liver injury.
  downstream:
  - target: Centrilobular Oncotic Hepatocyte Necrosis
    causal_link_type: DIRECT
    description: Irreversible mitochondrial failure and nuclear DNA fragmentation culminate in oncotic hepatocyte necrosis.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:22378043
      reference_title: The mechanism underlying acetaminophen-induced hepatotoxicity in humans and mice involves mitochondrial damage and nuclear DNA fragmentation.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "mitochondrial damage and nuclear DNA fragmentation are likely to be critical events in APAP hepatotoxicity in humans, resulting in necrotic cell death."
      explanation: The human study directly links mitochondrial damage and nuclear DNA fragmentation to necrotic cell death.
- name: Centrilobular Oncotic Hepatocyte Necrosis
  conforms_to: "drug_induced_liver_injury#Hepatocyte Cell Death"
  description: >-
    Irreversible mitochondrial injury produces predominantly oncotic necrosis in
    centrilobular hepatocytes. This is the central tissue lesion that releases
    aminotransferases and damage signals and reduces functional hepatic mass.
  role: central effector
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  locations:
  - preferred_term: liver
    term:
      id: UBERON:0002107
      label: liver
  biological_processes:
  - preferred_term: cell death
    term:
      id: GO:0008219
      label: cell death
    modifier: INCREASED
  evidence:
  - reference: PMID:1214189
    reference_title: "Histopathological changes in the liver following a paracetamol overdose: correlation with clinical and biochemical parameters."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Confluent centrilobular necrosis of varying extent was followed by rapid disappearance of necrotic cells"
    explanation: Biopsies from 104 patients directly establish the centrilobular necrotic lesion.
  - reference: PMID:38265880
    reference_title: "Acetaminophen Hepatotoxicity: Paradigm for Understanding Mechanisms of Drug-Induced Liver Injury."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Extensive evidence supports oncotic necrosis as the mode of cell death"
    explanation: The modern review supports oncotic necrosis as the predominant death mode.
  downstream:
  - target: Sterile Inflammatory and Regenerative Response
    causal_link_type: DIRECT
    description: Necrotic hepatocytes release damage signals that activate innate immune cells involved in injury containment and repair.
    hypothesis_groups:
    - sterile_inflammation_injury_repair_model
    evidence:
    - reference: PMID:36001996
      reference_title: "Management of Acute Liver Failure: Update 2022."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "toxin-induced (and presumably ischemia-induced) injuries do so via damage-associated molecular patterns (DAMPs)"
      explanation: The ALF review links toxin-induced necrotic injury to damage-associated immune signaling.
  - target: Acetaminophen-Induced Acute Liver Injury and Failure
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: Extensive hepatocyte loss reduces hepatic synthetic, metabolic, and detoxifying capacity and can culminate in acute liver failure.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:16317692
      reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Severe acetaminophen hepatotoxicity frequently leads to acute liver failure"
      explanation: The prospective human cohort supports progression from severe injury to acute liver failure.
  - target: Elevated hepatic transaminases
    causal_link_type: DIRECT
    description: Necrotic liver injury is accompanied by increased plasma aminotransferase activity.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:22378043
      reference_title: The mechanism underlying acetaminophen-induced hepatotoxicity in humans and mice involves mitochondrial damage and nuclear DNA fragmentation.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "closely followed the release of ALT, i.e., cell necrosis."
      explanation: Patient biomarker time courses directly link ALT release with necrotic cell death.
- name: Sterile Inflammatory and Regenerative Response
  description: >-
    Damage-associated signals from necrotic hepatocytes activate Kupffer cells,
    monocyte-derived macrophages, and neutrophils. These cells can participate
    in inflammatory injury, clearance of necrotic debris, and regeneration; the
    evidence does not justify a universal net-amplification edge to liver
    failure.
  role: context-dependent modifier
  cell_types:
  - preferred_term: Kupffer cell
    term:
      id: CL:0000091
      label: Kupffer cell
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  biological_processes:
  - preferred_term: inflammatory response
    term:
      id: GO:0006954
      label: inflammatory response
    modifier: INCREASED
  evidence:
  - reference: PMID:38265880
    reference_title: "Acetaminophen Hepatotoxicity: Paradigm for Understanding Mechanisms of Drug-Induced Liver Injury."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "sterile inflammation in injury and repair with activation of Kupffer cells, monocyte-derived macrophages, and neutrophils"
    explanation: The review supports the response while explicitly framing injury and repair roles.
  - reference: PMID:35905941
    reference_title: Generation of pro-and anti-inflammatory mediators after acetaminophen overdose in surviving and non-surviving patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the inflammatory response after APAP overdose in patients is not mediated by a second phase of inflammation driven by the inflammasome"
    explanation: Longitudinal patient cytokine data argue against a simple second injurious inflammasome phase.
- name: Acetaminophen-Induced Acute Liver Injury and Failure
  conforms_to: "drug_induced_liver_injury#Liver Injury and Acute Liver Failure"
  description: >-
    Loss of functional hepatocyte mass first produces biochemical acute liver
    injury and, in severe cases, hepatic synthetic failure, impaired
    detoxification, encephalopathy, and multiorgan complications. Jaundice may
    occur but is not required to define acute liver failure.
  role: consequence
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  locations:
  - preferred_term: liver
    term:
      id: UBERON:0002107
      label: liver
  evidence:
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"
    explanation: The multicenter cohort defines acute liver failure by coagulopathy and encephalopathy.
  - reference: PMID:36001996
    reference_title: "Management of Acute Liver Failure: Update 2022."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "acetaminophen toxicity, which evolves so rapidly that delay is likely to lead to death"
    explanation: The modern management review supports the hyperacute severity and need for early escalation.
  downstream:
  - target: Acute hepatic failure
    causal_link_type: DIRECT
    description: Severe injury crosses into loss of hepatic synthetic and detoxifying function.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:16317692
      reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Severe acetaminophen hepatotoxicity frequently leads to acute liver failure"
      explanation: The prospective cohort directly supports this severe transition.
  - target: Jaundice
    causal_link_type: DIRECT
    description: Severe loss of hepatic function may impair bilirubin handling and produce jaundice.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:35615243
      reference_title: Acute liver failure following paracetamol overdose.
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "coagulopathy of liver origin, jaundice and encephalopathy in a patient with no prior history of liver disease"
      explanation: The clinical review directly documents jaundice among manifestations that can accompany paracetamol-related acute liver failure.
  - target: Prolonged prothrombin time
    causal_link_type: DIRECT
    description: Loss of hepatic clotting-factor synthesis prolongs prothrombin time and increases INR.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:1214189
      reference_title: "Histopathological changes in the liver following a paracetamol overdose: correlation with clinical and biochemical parameters."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "correlated well with the clinical course and both the maximal prolongation of the prothrombin time"
      explanation: The biopsy series directly links loss of viable hepatic parenchyma to prolonged prothrombin time.
  - target: Hepatic encephalopathy
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: Failure of hepatic detoxification and systemic metabolic disturbance produce hepatic encephalopathy.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:16317692
      reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"
      explanation: The cohort identifies encephalopathy as a defining severe feature.
  - target: Acute kidney injury
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: Acetaminophen-induced acute liver failure can be complicated by acute kidney injury as part of systemic critical illness.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:36001996
      reference_title: "Management of Acute Liver Failure: Update 2022."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, sepsis"
      explanation: The modern ALF review identifies acute kidney injury among systemic complications.
  - target: Shock
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: Systemic inflammatory and circulatory failure can produce hypotension requiring vasopressor support.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:36001996
      reference_title: "Management of Acute Liver Failure: Update 2022."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "the systemic (extrahepatic) features of ALF (cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, sepsis)"
      explanation: The modern ALF review identifies cardiovascular collapse as a systemic consequence.
  - target: Increased intracranial pressure
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: Severe hepatic encephalopathy can progress through cerebral edema to intracranial hypertension.
    hypothesis_groups:
    - canonical_napqi_mitochondrial_necrosis_model
    evidence:
    - reference: PMID:32920216
      reference_title: "Clinical and Neurologic Outcomes in Acetaminophen-Induced Acute Liver Failure: A 21-Year Multicenter Cohort Study."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "less likely to develop intracranial hypertension (29.9% vs 51.5%; P < .001)"
      explanation: The 1,190-patient APAP-ALF cohort directly documents intracranial hypertension and cerebral edema.
phenotypes:
- name: Nausea and vomiting
  category: Early nonspecific manifestation
  description: >-
    Nausea and vomiting can occur during the initial post-ingestion phase.
  phenotype_term:
    preferred_term: Nausea and vomiting
    term:
      id: HP:0002017
      label: Nausea and vomiting
  evidence:
  - reference: PMID:6359859
    reference_title: Acetaminophen overdose.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Symptoms of nausea, vomiting, diaphoresis, and anorexia usually begin within seven to 14 hours after ingestion."
    explanation: The clinical review directly identifies nausea and vomiting in the initial stage.
- name: Elevated hepatic transaminases
  category: Hepatocellular injury
  description: >-
    Rising ALT and AST report hepatocyte injury and can become marked. They are
    injury markers rather than direct measures of hepatic synthetic function.
  phenotype_term:
    preferred_term: Elevated hepatic transaminases
    term:
      id: HP:0002910
      label: Elevated circulating hepatic transaminase concentration
  reports_on:
  - target: Centrilobular hepatocyte necrosis
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: Serum transaminase elevation reflects ongoing centrilobular hepatocyte necrosis.
  evidence:
  - reference: PMID:28421844
    reference_title: Accuracy of the paracetamol-aminotransferase multiplication product to predict hepatotoxicity in modified-release paracetamol overdose.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hepatotoxicity was defined as peak alanine aminotransferase ≥1000 IU/L"
    explanation: The modified-release cohort uses marked ALT elevation to define hepatotoxicity.
- name: Acute hepatic failure
  category: Severe hepatic outcome
  description: >-
    Acute hepatic failure is the severe outcome characterized by acute liver
    injury with coagulopathy and encephalopathy in a patient with no prior
    history of liver disease. It is not an inevitable consequence of overdose.
  phenotype_term:
    preferred_term: Acute hepatic failure
    term:
      id: HP:0006554
      label: Acute hepatic failure
  evidence:
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"
    explanation: The multicenter cohort applies standard acute liver failure criteria.
  - reference: PMID:35615243
    reference_title: Acute liver failure following paracetamol overdose.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "in a patient with no prior history of liver disease"
    explanation: The clinical review directly supports exclusion of known preexisting liver disease from the acute-liver-failure definition.
- name: Jaundice
  category: Severe hepatic manifestation
  description: >-
    Jaundice may occur during severe injury, but it is not required by the
    coagulopathy-and-encephalopathy criteria used in the prospective acute liver
    failure cohort.
  phenotype_term:
    preferred_term: Jaundice
    term:
      id: HP:0000952
      label: Jaundice
  evidence:
  - reference: PMID:35615243
    reference_title: Acute liver failure following paracetamol overdose.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "coagulopathy of liver origin, jaundice and encephalopathy in a patient with no prior history of liver disease"
    explanation: The clinical review directly supports jaundice as a manifestation that can accompany paracetamol-related acute liver failure.
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"
    explanation: The multicenter cohort's standard criteria support the caveat that jaundice is not required to define acute liver failure.
- name: Prolonged prothrombin time
  category: Hepatic synthetic dysfunction
  description: >-
    Prolonged prothrombin time and increased INR reflect impaired hepatic
    clotting-factor synthesis and are followed serially during severe injury.
  phenotype_term:
    preferred_term: Prolonged prothrombin time
    term:
      id: HP:0008151
      label: Prolonged prothrombin time
  evidence:
  - reference: PMID:1214189
    reference_title: "Histopathological changes in the liver following a paracetamol overdose: correlation with clinical and biochemical parameters."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "correlated well with the clinical course and both the maximal prolongation of the prothrombin time"
    explanation: The biopsy cohort links loss of viable liver parenchyma to prolonged prothrombin time.
- name: Hepatic encephalopathy
  category: Neurologic complication of acute liver failure
  description: >-
    Hepatic encephalopathy marks severe functional failure and may progress to
    cerebral edema and intracranial hypertension.
  phenotype_term:
    preferred_term: Hepatic encephalopathy
    term:
      id: HP:0002480
      label: Hepatic encephalopathy
  evidence:
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"
    explanation: The multicenter cohort identifies encephalopathy as a defining severe feature.
- name: Metabolic acidosis
  category: Severe metabolic complication
  description: >-
    Severe metabolic acidosis can occur early after an exceptionally large
    overdose, before hepatic failure.
  phenotype_term:
    preferred_term: Metabolic acidosis
    term:
      id: HP:0001942
      label: Metabolic acidosis
  evidence:
  - reference: PMID:25133498
    reference_title: "Extracorporeal treatment for acetaminophen poisoning: recommendations from the EXTRIP workgroup."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "early development of altered mental status and severe metabolic acidosis prior to the onset of hepatic failure"
    explanation: EXTRIP documents the early mitochondrial-toxicity presentation.
- name: Acute kidney injury
  category: Extrahepatic complication
  description: >-
    Acute kidney injury can accompany acetaminophen-induced acute liver failure
    as part of systemic critical illness.
  phenotype_term:
    preferred_term: Acute kidney injury
    term:
      id: HP:0001919
      label: Acute kidney injury
  evidence:
  - reference: PMID:36001996
    reference_title: "Management of Acute Liver Failure: Update 2022."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, sepsis"
    explanation: The modern ALF review lists acute kidney injury among systemic complications.
- name: Shock
  category: Extrahepatic complication
  description: >-
    Cardiovascular collapse and vasopressor-requiring hypotension can develop in
    severe acute liver failure and multiorgan dysfunction.
  phenotype_term:
    preferred_term: Shock
    term:
      id: HP:0031273
      label: Shock
  evidence:
  - reference: PMID:36001996
    reference_title: "Management of Acute Liver Failure: Update 2022."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "the systemic (extrahepatic) features of ALF (cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, sepsis)"
    explanation: The modern review identifies cardiovascular collapse as an extrahepatic ALF consequence.
- name: Increased intracranial pressure
  category: Neurologic complication of acute liver failure
  description: >-
    Intracranial hypertension from cerebral edema is a life-threatening
    complication of severe hepatic encephalopathy. Its frequency has fallen in
    more recent cohorts but it remains clinically important.
  phenotype_term:
    preferred_term: Increased intracranial pressure
    term:
      id: HP:0002516
      label: Increased intracranial pressure
  evidence:
  - reference: PMID:32920216
    reference_title: "Clinical and Neurologic Outcomes in Acetaminophen-Induced Acute Liver Failure: A 21-Year Multicenter Cohort Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "less likely to develop intracranial hypertension (29.9% vs 51.5%; P < .001)"
    explanation: The large APAP-ALF cohort directly documents the neurologic complication and its temporal decline.
biochemical:
- name: Serum acetaminophen concentration
  presence: INCREASED
  context: >-
    A timed serum concentration reports systemic exposure. Its interpretation is
    time-, formulation-, and ingestion-pattern dependent; a low or undetectable
    level in a late presenter does not exclude established hepatic injury.
  readouts:
  - target: Supratherapeutic Acetaminophen Exposure
    relationship: READOUT_OF
    direction: THRESHOLD_DEPENDENT
    endpoint_context: DIAGNOSTIC
    interpretation: A properly timed concentration can quantify exposure risk only within an applicable acute-ingestion pathway.
    evidence:
    - reference: PMID:34053705
      reference_title: Acetaminophen Poisoning.
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "The acetaminophen nomogram is used to assess the need for treatment in acute immediate-release overdoses with a known time of ingestion."
      explanation: The review supplies the restricted context for interpreting the concentration.
  evidence:
  - reference: PMID:33778331
    reference_title: "Acute Liver Failure of unclear cause? Acetaminophen-protein adducts make the diagnosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the acetaminophen concentration is low or undetectable at arrival to care"
    explanation: The clinical report directly documents that a low or undetectable arrival concentration can coexist with acetaminophen-related acute liver failure.
  - reference: PMID:37552484
    reference_title: "Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "A revised form of the Rumack-Matthew nomogram was developed."
    explanation: The consensus includes time-dependent serum concentration interpretation in acute ingestion management.
- name: Serum alanine and aspartate aminotransferases
  presence: INCREASED
  context: >-
    Serial ALT and AST report hepatocyte injury and can rise after early
    symptoms improve. They do not by themselves measure hepatic function.
  readouts:
  - target: Centrilobular Oncotic Hepatocyte Necrosis
    relationship: CORRELATES_WITH
    direction: POSITIVE
    endpoint_context: MONITORING
    interpretation: Rising aminotransferases reflect increasing hepatocyte injury and membrane release.
    evidence:
    - reference: PMID:28421844
      reference_title: Accuracy of the paracetamol-aminotransferase multiplication product to predict hepatotoxicity in modified-release paracetamol overdose.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Hepatotoxicity was defined as peak alanine aminotransferase ≥1000 IU/L"
      explanation: The direct cohort links marked ALT elevation to hepatotoxicity.
  evidence:
  - reference: PMID:37683599
    reference_title: "Paracetamol (acetaminophen) poisoning: The early years."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "maximum abnormalities of liver function were delayed for 3 days or more after an overdose"
    explanation: The review supports delayed peak laboratory abnormalities and serial assessment.
- name: International normalized ratio
  presence: INCREASED
  context: >-
    Rising INR reflects hepatic synthetic failure rather than the magnitude of
    hepatocyte enzyme release and contributes to serial severity assessment.
  readouts:
  - target: Acetaminophen-Induced Acute Liver Injury and Failure
    relationship: CORRELATES_WITH
    direction: POSITIVE
    endpoint_context: PROGNOSTIC
    interpretation: Higher and worsening INR indicates loss of hepatic synthetic function and more severe disease.
    evidence:
    - reference: PMID:1214189
      reference_title: "Histopathological changes in the liver following a paracetamol overdose: correlation with clinical and biochemical parameters."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "correlated well with the clinical course and both the maximal prolongation of the prothrombin time"
      explanation: Human biopsy data link loss of viable parenchyma to prothrombin-time prolongation.
  evidence:
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"
    explanation: The cohort supports coagulopathy as a defining functional-failure marker.
- name: Serum acetaminophen-protein adducts
  presence: INCREASED
  context: >-
    APAP-cysteine protein adducts report NAPQI-mediated protein binding and may
    help identify acetaminophen etiology when exposure history or the parent-drug
    concentration is unavailable. The assay is specialized rather than a routine
    bedside test.
  readouts:
  - target: NAPQI Formation, Protein Adduction, and Glutathione Depletion
    relationship: READOUT_OF
    direction: PRESENT_ABSENT
    endpoint_context: DIAGNOSTIC
    interpretation: Detectable serum adducts provide evidence of hepatic NAPQI-protein binding and hepatocyte lysis.
    evidence:
    - reference: PMID:16530510
      reference_title: Measurement of serum acetaminophen-protein adducts in patients with acute liver failure.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Acetaminophen-protein adducts were detected in serum in 100% of known acetaminophen ALF patients"
      explanation: The multicenter study directly supports the diagnostic readout in known APAP-ALF.
  evidence:
  - reference: PMID:19439490
    reference_title: Pharmacokinetics of acetaminophen-protein adducts in adults with acetaminophen overdose and acute liver failure.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Adducts were detected in some patient samples 12 days post-ingestion."
    explanation: Human pharmacokinetic data support persistence beyond the parent-drug detection window.
- name: Circulating CXCL14
  presence: INCREASED
  context: >-
    CXCL14 is a research-stage prognostic candidate in acetaminophen-induced
    acute liver failure. Discovery and independent-validation cohorts are
    promising, but external validation and routine clinical implementation are
    not established.
  readouts:
  - target: Acetaminophen-Induced Acute Liver Injury and Failure
    relationship: PREDICTS
    direction: POSITIVE
    endpoint_context: PROGNOSTIC
    interpretation: Higher early CXCL14 was associated with death or transplantation in the studied cohorts; it is not an established transplant selector.
    evidence:
    - reference: PMID:37910653
      reference_title: The chemokine CXCL14 is a novel early prognostic biomarker for poor outcome in acetaminophen-induced acute liver failure.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "We find in 2 independent cohorts of acetaminophen overdose patients that circulating CXCL14 concentration is a novel early prognostic biomarker"
      explanation: The primary study supplies discovery and independent validation evidence.
  evidence:
  - reference: PMID:37910653
    reference_title: The chemokine CXCL14 is a novel early prognostic biomarker for poor outcome in acetaminophen-induced acute liver failure.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "combining MELD and CXCL14 yielded the best AUC (0.860)"
    explanation: The study supports incremental prognostic association while remaining a research-stage result.
treatments:
- name: N-acetylcysteine
  description: >-
    N-acetylcysteine (NAC) is the established antidote. It is most protective
    when started early, but treatment remains beneficial when presentation is
    delayed or acute liver failure is established. Regimen selection and
    stopping require clinical assessment; no single intensified regimen or
    bedside stopping protocol is asserted here.
  action_category: THERAPEUTIC
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: antidote agent therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: acetylcysteine
      term:
        id: NCIT:C200
        label: Acetylcysteine
  target_mechanisms:
  - target: NAPQI Formation, Protein Adduction, and Glutathione Depletion
    treatment_effect: INHIBITS
    description: NAC supplies cysteine for glutathione restoration and increases capacity to detoxify reactive metabolite.
    evidence:
    - reference: PMID:24905542
      reference_title: Mechanisms of acetaminophen-induced cell death in primary human hepatocytes.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "improved scavenging of the reactive metabolite NAPQI due to accelerated GSH synthesis"
      explanation: The human-hepatocyte study directly states the early glutathione-dependent mechanism represented by this inhibitory edge.
  target_phenotypes:
  - preferred_term: Acute hepatic failure
    term:
      id: HP:0006554
      label: Acute hepatic failure
  evidence:
  - reference: PMID:3059186
    reference_title: Efficacy of oral N-acetylcysteine in the treatment of acetaminophen overdose. Analysis of the national multicenter study (1976 to 1985).
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "When given within eight hours of acetaminophen ingestion, N-acetylcysteine was protective regardless of the initial plasma acetaminophen concentration."
    explanation: The large multicenter study directly supports strong early clinical efficacy.
  - reference: PMID:1954453
    reference_title: "Intravenous acetylcysteine in paracetamol induced fulminant hepatic failure: a prospective controlled trial."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The rate of survival was significantly higher in the acetylcysteine treated group than in the controls"
    explanation: The prospective controlled trial supports benefit after fulminant hepatic failure is established.
  - reference: PMID:37552484
    reference_title: "Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "detailed management of acetylcysteine treatment, associated adverse effects, and stopping criteria"
    explanation: The multisociety consensus confirms that treatment management and stopping require explicit criteria, without this entry asserting a bedside protocol.
- name: Activated charcoal gastrointestinal decontamination
  description: >-
    Patients who present early after acute acetaminophen poisoning should be
    offered activated charcoal as gastrointestinal decontamination.
  action_category: THERAPEUTIC
  treatment_term:
    preferred_term: pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: charcoal
      term:
        id: CHEBI:91090
        label: charcoal
  evidence:
  - reference: PMID:34053705
    reference_title: Acetaminophen Poisoning.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Patients who present early should be offered activated charcoal"
    explanation: The toxicology review directly supports early decontamination after acute exposure.
  - reference: PMID:37552484
    reference_title: "Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "defining the role of gastrointestinal decontamination"
    explanation: The consensus includes exposure-pattern-specific gastrointestinal decontamination guidance.
- name: Intermittent hemodialysis for exceptional high-risk poisoning
  description: >-
    Extracorporeal removal is not warranted in most acetaminophen poisonings
    because NAC is effective. Intermittent hemodialysis is a rare adjunct for
    exceptionally large exposure with early mitochondrial dysfunction such as
    altered consciousness and severe metabolic acidosis. The recommendation is
    based on very-low-quality evidence and accompanies, rather than replaces,
    antidotal care.
  action_category: THERAPEUTIC
  treatment_term:
    preferred_term: hemodialysis
    term:
      id: NCIT:C15248
      label: Hemodialysis
  target_mechanisms:
  - target: Supratherapeutic Acetaminophen Exposure
    treatment_effect: INHIBITS
    description: Hemodialysis removes circulating acetaminophen during the exceptional early high-concentration state.
    evidence:
    - reference: PMID:25133498
      reference_title: "Extracorporeal treatment for acetaminophen poisoning: recommendations from the EXTRIP workgroup."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "APAP is amenable to extracorporeal removal."
      explanation: EXTRIP directly supports removal of circulating acetaminophen by extracorporeal treatment.
  target_phenotypes:
  - preferred_term: Metabolic acidosis
    term:
      id: HP:0001942
      label: Metabolic acidosis
  evidence:
  - reference: PMID:25133498
    reference_title: "Extracorporeal treatment for acetaminophen poisoning: recommendations from the EXTRIP workgroup."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "ECTR is not warranted in most cases of APAP poisoning"
    explanation: The workgroup explicitly restricts extracorporeal treatment to exceptional cases.
  - reference: PMID:25133498
    reference_title: "Extracorporeal treatment for acetaminophen poisoning: recommendations from the EXTRIP workgroup."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "yielding an overall very low quality of evidence for all recommendations"
    explanation: The source directly calibrates the certainty of its recommendation.
- name: Fomepizole as an investigational adjunct
  description: >-
    Fomepizole inhibits CYP2E1 and JNK in mechanistic studies and has been used
    off label with NAC in selected high-risk cases. A small uncontrolled case
    series supports safety and feasibility, but a much larger comparative cohort
    found no clinical outcome benefit. Routine use is unsupported; any
    consideration belongs under specialist toxicology guidance.
  action_category: THERAPEUTIC
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: antidote agent therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: fomepizole
      term:
        id: CHEBI:5141
        label: fomepizole
  target_mechanisms:
  - target: NAPQI Formation, Protein Adduction, and Glutathione Depletion
    treatment_effect: INHIBITS
    description: Proposed CYP2E1 inhibition could reduce additional NAPQI formation; this mechanistic rationale is not proof of clinical benefit.
    evidence:
    - reference: PMID:34709101
      reference_title: "Fomepizole as an adjunct in acetylcysteine treated acetaminophen overdose patients: a case series."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "is a potent CYP2E1 and c-Jun-N-terminal Kinase (JNK) inhibitor"
      explanation: The prospective case series states the mechanistic rationale but cannot establish comparative efficacy.
  evidence:
  - reference: PMID:34709101
    reference_title: "Fomepizole as an adjunct in acetylcysteine treated acetaminophen overdose patients: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This case series has demonstrated the safety of fomepizole in high-risk APAP overdose."
    explanation: Fourteen selected patients provide limited safety and feasibility evidence without a control group.
  - reference: PMID:34709101
    reference_title: "Fomepizole as an adjunct in acetylcysteine treated acetaminophen overdose patients: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The efficacy of fomepizole needs to be further elucidated through controlled clinical trials on a larger scale."
    explanation: The investigators explicitly acknowledge that efficacy is unresolved.
  - reference: PMID:41886998
    reference_title: Clinical impact of fomepizole as an adjunct therapy in high-risk acetaminophen overdose.
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "Fomepizole as an adjunct to N-acetylcysteine in patients with high-risk acetaminophen overdose did not improve clinical outcomes"
    explanation: The 391-patient comparative cohort directly refutes a claim of demonstrated routine outcome benefit.
  notes: Emerging and off-label; not a substitute for NAC and not represented as standard care.
- name: Supportive critical care for acute liver failure
  description: >-
    Severe acute liver failure requires serial neurologic, metabolic,
    coagulation, renal, respiratory, and hemodynamic assessment with organ
    support as indicated, including cardiovascular, respiratory, and renal
    support and management of encephalopathy and cerebral edema.
  action_category: THERAPEUTIC
  treatment_term:
    preferred_term: supportive care
    term:
      id: NCIT:C15747
      label: Supportive Care
  target_phenotypes:
  - preferred_term: Hepatic encephalopathy
    term:
      id: HP:0002480
      label: Hepatic encephalopathy
  - preferred_term: Acute kidney injury
    term:
      id: HP:0001919
      label: Acute kidney injury
  - preferred_term: Shock
    term:
      id: HP:0031273
      label: Shock
  evidence:
  - reference: PMID:36001996
    reference_title: "Management of Acute Liver Failure: Update 2022."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Management involves optimizing fluid balance and cardiovascular support, including the use of continuous renal replacement therapy, vasopressors, and pulmonary ventilation."
    explanation: The modern review supports multidisciplinary organ support in acute liver failure.
- name: Early transplant-center evaluation and liver transplantation
  description: >-
    Progressive coagulopathy, encephalopathy, or multiorgan failure despite
    antidotal and critical care should trigger early transplant-center
    evaluation. Prognostic scores and serial trends inform multidisciplinary
    judgment but are imperfect; transplantation is a rescue option for patients
    judged unlikely to survive with medical therapy alone.
  action_category: THERAPEUTIC
  treatment_term:
    preferred_term: liver transplantation
    term:
      id: NCIT:C15271
      label: Liver Transplantation
  target_phenotypes:
  - preferred_term: Acute hepatic failure
    term:
      id: HP:0006554
      label: Acute hepatic failure
  - preferred_term: Hepatic encephalopathy
    term:
      id: HP:0002480
      label: Hepatic encephalopathy
  evidence:
  - reference: PMID:36001996
    reference_title: "Management of Acute Liver Failure: Update 2022."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Early evaluation for liver transplantation is advised particularly for acetaminophen toxicity"
    explanation: The modern ALF update supports early evaluation rather than waiting for irreversible deterioration.
  - reference: PMID:36001996
    reference_title: "Management of Acute Liver Failure: Update 2022."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "provide reasonable but imperfect predictive accuracy"
    explanation: The review calibrates prognostic scores as decision support rather than absolute rules.
diagnosis:
- name: Timed serum acetaminophen concentration and nomogram assessment
  description: >-
    A serum concentration obtained at an interpretable time can be plotted on
    the Rumack-Matthew nomogram for an acute immediate-release overdose with a
    known ingestion time. Modified-release, large, and repeated supratherapeutic
    ingestions require different assessment pathways.
  diagnosis_term:
    preferred_term: blood chemistry measurement
    term:
      id: NCIT:C47868
      label: Blood Chemistry Measurement
  results: Time-dependent concentration interpretation identifies an acute-ingestion treatment-risk category; it does not independently diagnose established hepatic injury.
  evidence:
  - reference: PMID:34053705
    reference_title: Acetaminophen Poisoning.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The acetaminophen nomogram is used to assess the need for treatment in acute immediate-release overdoses with a known time of ingestion."
    explanation: The toxicology review defines the core nomogram scope.
  - reference: PMID:37552484
    reference_title: "Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "A revised form of the Rumack-Matthew nomogram was developed."
    explanation: The multisociety consensus is the current North American framework for nomogram-based assessment.
- name: Serial liver-injury and liver-failure assessment
  description: >-
    Serial ALT and AST trends report hepatocellular injury, while bilirubin and
    PT or INR report evolving excretory and synthetic dysfunction. Coagulopathy
    together with encephalopathy identifies progression to acute liver failure.
  diagnosis_term:
    preferred_term: clinical laboratory procedure
    term:
      id: NCIT:C25294
      label: Laboratory Procedure
  markers: ALT, AST, bilirubin, PT/INR, and clinical encephalopathy assessment
  results: Rising aminotransferases indicate injury; worsening bilirubin or PT/INR and development of encephalopathy indicate functional progression.
  evidence:
  - reference: PMID:6359859
    reference_title: Acetaminophen overdose.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "SGOT, SGPT, bilirubin, and prothrombin time begin to rise."
    explanation: The clinical review directly identifies the serial laboratory abnormalities retained here.
  - reference: PMID:16317692
    reference_title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "fulfilling standard criteria for ALF (coagulopathy and encephalopathy)"
    explanation: The multicenter cohort directly supports the functional-failure assessment.
- name: Serum acetaminophen-protein adduct analysis
  description: >-
    Specialized serum APAP-protein adduct measurement can support an
    acetaminophen etiology in late or indeterminate acute liver failure when
    history is unavailable or the acetaminophen concentration is low or
    undetectable at arrival. It is an adjunct and is not assumed to be routinely
    available.
  diagnosis_term:
    preferred_term: biomarker analysis
    term:
      id: NCIT:C63333
      label: Biomarker Analysis
  results: Detectable APAP-protein adducts support NAPQI-mediated acetaminophen toxicity in the appropriate acute liver injury context.
  evidence:
  - reference: PMID:33778331
    reference_title: "Acute Liver Failure of unclear cause? Acetaminophen-protein adducts make the diagnosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the acetaminophen concentration is low or undetectable at arrival to care"
    explanation: The clinical report directly supports using adducts when the parent-drug concentration is no longer diagnostic.
  - reference: PMID:33778331
    reference_title: "Acute Liver Failure of unclear cause? Acetaminophen-protein adducts make the diagnosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "APAP-protein adduct measurement by HPLC-EC or LC-MS/MS remains experimental and limited to research centers"
    explanation: The report directly calibrates current assay availability and supports treating adduct testing as a specialized adjunct.
  - reference: PMID:16530510
    reference_title: Measurement of serum acetaminophen-protein adducts in patients with acute liver failure.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Measurement of serum acetaminophen-protein adducts reliably identified acetaminophen toxicity"
    explanation: The prospective multicenter study directly supports etiologic diagnostic utility.
  - reference: PMID:19439490
    reference_title: Pharmacokinetics of acetaminophen-protein adducts in adults with acetaminophen overdose and acute liver failure.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Adducts were detected in some patient samples 12 days post-ingestion."
    explanation: The pharmacokinetic study directly demonstrates prolonged persistence of the biomarker.
differential_diagnoses:
- name: Ischemic or hypoxic acute liver injury
  description: >-
    Ischemic injury and acetaminophen toxicity are both hyperacute causes of
    acute liver failure, so their clinical time courses can overlap.
  distinguishing_features:
  - Acetaminophen-protein adducts were specific for acetaminophen-related acute liver failure against other defined causes in the cited cohort.
  evidence:
  - reference: PMID:36001996
    reference_title: "Management of Acute Liver Failure: Update 2022."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Most causes of ALF can be divided into hyperacute (ischemia and acetaminophen) and subacute types"
    explanation: The review directly places ischemia and acetaminophen in the overlapping hyperacute differential.
  - reference: PMID:16530510
    reference_title: Measurement of serum acetaminophen-protein adducts in patients with acute liver failure.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acetaminophen-protein adducts were detected in serum in 100% of known acetaminophen ALF patients and in none of the ALF patients with other defined causes"
    explanation: The prospective cohort directly supports adduct testing as a discriminator from other defined acute-liver-failure causes.
- name: Fulminant viral hepatitis
  description: >-
    Viral etiologies are a distinct cause of acute liver failure and engage
    pathogen-associated immune signaling, whereas toxin-induced injury engages
    damage-associated signaling.
  disease_term:
    preferred_term: fulminant viral hepatitis
    term:
      id: MONDO:0018109
      label: fulminant viral hepatitis
  distinguishing_features:
  - The cited acute-liver-failure review distinguishes viral PAMP signaling from toxin-induced DAMP signaling.
  evidence:
  - reference: PMID:36001996
    reference_title: "Management of Acute Liver Failure: Update 2022."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Injuries by viral etiologies trigger the innate immune system via pathogen-associated molecular patterns (PAMPs), while toxin-induced (and presumably ischemia-induced) injuries do so via damage-associated molecular patterns (DAMPs)."
    explanation: The ALF update directly distinguishes viral PAMP signaling from toxin-induced DAMP signaling.
- name: Other drug-induced liver injury
  description: >-
    Other drug-related or defined causes can produce acute liver failure, but
    the cited prospective cohort found acetaminophen-protein adducts only in
    acetaminophen-related cases among its defined-cause comparison groups.
  disease_term:
    preferred_term: drug-induced liver injury
    term:
      id: MONDO:0005359
      label: drug-induced liver injury
  distinguishing_features:
  - Acetaminophen-protein adducts support acetaminophen toxicity over another defined acute-liver-failure cause in the cited cohort.
  evidence:
  - reference: PMID:16530510
    reference_title: Measurement of serum acetaminophen-protein adducts in patients with acute liver failure.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acetaminophen-protein adducts were detected in serum in 100% of known acetaminophen ALF patients and in none of the ALF patients with other defined causes"
    explanation: The prospective cohort directly supports adduct specificity against its other defined acute-liver-failure causes.
references:
- reference: PMID:1214189
  title: "Histopathological changes in the liver following a paracetamol overdose: correlation with clinical and biochemical parameters."
- reference: PMID:16317692
  title: "Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study."
- reference: PMID:16530510
  title: Measurement of serum acetaminophen-protein adducts in patients with acute liver failure.
- reference: PMID:19439490
  title: Pharmacokinetics of acetaminophen-protein adducts in adults with acetaminophen overdose and acute liver failure.
- reference: PMID:1954453
  title: "Intravenous acetylcysteine in paracetamol induced fulminant hepatic failure: a prospective controlled trial."
- reference: PMID:22378043
  title: The mechanism underlying acetaminophen-induced hepatotoxicity in humans and mice involves mitochondrial damage and nuclear DNA fragmentation.
- reference: PMID:24905542
  title: Mechanisms of acetaminophen-induced cell death in primary human hepatocytes.
- reference: PMID:25133498
  title: "Extracorporeal treatment for acetaminophen poisoning: recommendations from the EXTRIP workgroup."
- reference: PMID:28421844
  title: Accuracy of the paracetamol-aminotransferase multiplication product to predict hepatotoxicity in modified-release paracetamol overdose.
- reference: PMID:3059186
  title: Efficacy of oral N-acetylcysteine in the treatment of acetaminophen overdose. Analysis of the national multicenter study (1976 to 1985).
- reference: PMID:32920216
  title: "Clinical and Neurologic Outcomes in Acetaminophen-Induced Acute Liver Failure: A 21-Year Multicenter Cohort Study."
- reference: PMID:33778331
  title: "Acute Liver Failure of unclear cause? Acetaminophen-protein adducts make the diagnosis."
- reference: PMID:34053705
  title: Acetaminophen Poisoning.
- reference: PMID:34709101
  title: "Fomepizole as an adjunct in acetylcysteine treated acetaminophen overdose patients: a case series."
- reference: PMID:35024303
  title: Recommendations for the use of the acetaminophen hepatotoxicity model for mechanistic studies and how to avoid common pitfalls.
- reference: PMID:35615243
  title: Acute liver failure following paracetamol overdose.
- reference: PMID:35905941
  title: Generation of pro-and anti-inflammatory mediators after acetaminophen overdose in surviving and non-surviving patients.
- reference: PMID:36001996
  title: "Management of Acute Liver Failure: Update 2022."
- reference: PMID:36670547
  title: The molecular mechanisms of acetaminophen-induced hepatotoxicity and its potential therapeutic targets.
- reference: PMID:37552484
  title: "Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement."
- reference: PMID:37683599
  title: "Paracetamol (acetaminophen) poisoning: The early years."
- reference: PMID:37910653
  title: The chemokine CXCL14 is a novel early prognostic biomarker for poor outcome in acetaminophen-induced acute liver failure.
- reference: PMID:38265880
  title: "Acetaminophen Hepatotoxicity: Paradigm for Understanding Mechanisms of Drug-Induced Liver Injury."
- reference: PMID:40047505
  title: "Out-of-hospital assessment and triage of paracetamol (acetaminophen) exposure in the United States and Canada: a consensus guideline."
- reference: PMID:41886998
  title: Clinical impact of fomepizole as an adjunct therapy in high-risk acetaminophen overdose.
- reference: PMID:6359859
  title: Acetaminophen overdose.
review_notes: >-
  Comprehensively re-reviewed in July 2026. The revision narrows identity from
  broad poisoning to acquired intrinsic acetaminophen liver injury; distinguishes
  acute immediate-release, modified-release, and repeated supratherapeutic
  exposure patterns; adds a source-calibrated four-phase clinical course and
  cohort epidemiology without inferring population prevalence; rebuilds the
  pathograph as a typed NAPQI-protein-adduct, mitochondrial-stress,
  DNA-fragmentation, centrilobular-oncotic-necrosis chain; and separates sterile
  inflammation into a context-dependent injury-and-repair branch. It corrects
  acute-liver-failure and hepatic-encephalopathy ontology bindings, adds early
  and systemic complications, links biomarkers to graph nodes, restricts the
  nomogram to applicable acute-ingestion contexts, and adds serial laboratory
  and specialized adduct diagnosis. Management now distinguishes established
  NAC, early charcoal, rare hemodialysis, supportive critical care, and early
  transplant evaluation from investigational fomepizole, whose routine outcome
  benefit is unsupported by current comparative evidence. Remaining evidence
  gaps include controlled fomepizole efficacy, an optimal intensified NAC
  regimen for selected high-risk exposure, broad clinical access to adduct
  testing, external validation of CXCL14, and resolution of the net human role
  of sterile inflammation across injury and repair.
clinical_trials: []
datasets:
- accession: geo:GSE284273
  title: Dendritic cell iron overload exacerbates acetaminophen hepatotoxicity
  description: Liver immune homeostasis relies on the coordinated actions of various immune cells including dendritic cells (DCs), which exert regulatory roles in both innate and adaptive immunity. Various pieces of evidence demonstrate that the properties of immune cells are highly influenced by iron metabolism. However, the roles of iron metabolism on DC function remain poorly understood. Here, we show that mice with iron overload in DCs displayed worsening of liver injury and mortality in acetaminophen (APAP) -induced acute hepatitis. Enhanced neutrophil infiltration was observed in these mice during the progression of liver injury.
  organism:
    preferred_term: mouse
    term:
      id: NCBITaxon:10090
      label: Mus musculus
  data_type: BULK_RNA_SEQ
  sample_count: 12
  publication: PMID:41120657
  notes: Identified by GEO DataSets index search for Acetaminophen Hepatotoxicity (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
- accession: geo:GSE305543
  title: Hepatocyte-specific MET deletion exacerbates acetaminophen-induced hepatotoxicity in mice
  description: Despite the well-known role of MET in liver regeneration following partial-hepatectomy (PHx), its role in the clinically-relevant acetaminophen (APAP)-induced liver injury (AILI) model remains unexplored. AILI markedly differs from PHx because it is associated with massive liver necrosis. This study aims to delineate the role of MET specifically in AILI. Hepatocyte-specific MET-KO mice were given a toxic-dose of APAP and assessed for hepatotoxicity/regeneration parameters. MET deletion strikingly exacerbated initial hepatotoxicity and impaired subsequent proliferative response, culminating in significant mortality.
  organism:
    preferred_term: mouse
    term:
      id: NCBITaxon:10090
      label: Mus musculus
  data_type: BULK_RNA_SEQ
  sample_count: 18
  publication: PMID:41038273
  notes: Identified by GEO DataSets index search for Acetaminophen Hepatotoxicity (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
- accession: massive:MSV000093653
  title: 'Raw data for manuscript : "Serine synthesis via reversed SHMT2 activity drives glycine depletion and acetaminophen hepatotoxicity in MASLD"'
  description: Metabolic dysfunction-associated steatotic liver disease (MASLD) affects one third of the global population. Understanding metabolic pathways involved can provide insights into disease progression and treatment. Untargeted metabolomics of livers from mice with early-stage steatosis uncovered decreased methylated metabolites, suggesting altered one-carbon metabolism. The levels of glycine, a central component of one-carbon metabolism, were lower in mice with hepatic steatosis, consistent with clinical evidence.
  notes: Located via OmicsDI, which aggregates across omics repositories; this record comes from massive. Only repositories with no other discovery route in this project and with a working accession resolver are curated from OmicsDI -- GEO, ArrayExpress, PRIDE, MetaboLights and EGA hits are excluded as duplicates of dedicated passes. Matched because the disease is named in the dataset's own title ("Acetaminophen Hepatotoxicity"). Retrieved 2026-08-02.

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References & Deep Research

References

26

PMID:1214189

Histopathological changes in the liver following a paracetamol overdose: correlation with clinical and biochemical parameters.