Severe hepatotoxicity after therapeutic doses of acetaminophen

Oswald Moling1, Elena Cairon, Giovanni Rimenti

  • 1Division of Infectious Diseases, Ospedale Generale, Bolzano, Italy. molosw@hotmail.com

Clinical Therapeutics
|July 25, 2006
PubMed
Abstract

Insights

Severe liver injury from acetaminophen at therapeutic doses can occur, especially with risk factors. Prompt N-acetylcysteine treatment effectively resolved acetaminophen-induced hepatotoxicity in a patient with multiple comorbidities.

Area of Science:

  • Hepatology
  • Clinical Toxicology
  • Pharmacology

Background:

  • Acetaminophen overdose is a common cause of acute liver failure.
  • The association between therapeutic acetaminophen doses and severe hepatotoxicity remains controversial.
  • Multiple risk factors can increase susceptibility to acetaminophen-induced liver injury.

Observation:

  • A patient with HIV, hepatitis B, and hepatitis C presented with severe hepatotoxicity after taking acetaminophen 1,000 mg four times daily for four days.
  • The patient exhibited significantly elevated liver enzymes (AST, ALT) and a high prothrombin international normalized ratio.
  • Potential risk factors including chronic infections and malnutrition were present.

Findings:

  • Continuous intravenous N-acetylcysteine administration led to rapid clinical improvement.
  • Liver enzyme levels (AST, ALT) decreased dramatically within 11 days of treatment.
  • N-acetylcysteine was effective in treating severe hepatotoxicity in this patient.

Implications:

  • This case highlights the potential for severe liver injury even at therapeutic acetaminophen doses in patients with risk factors.
  • Early recognition and prompt N-acetylcysteine treatment are crucial for managing acetaminophen-induced hepatotoxicity.
  • Further research may clarify the precise mechanisms and risk stratification for acetaminophen hepatotoxicity at therapeutic doses.

Related Concept Videos

Drug Toxicity: Dose-Dependent Reactions01:24

Drug Toxicity: Dose-Dependent Reactions

Drug toxicities can be stratified into pharmacological, pathological, or genotoxic based on their mechanisms. The incidence and severity of these toxicities generally increase with the drug's concentration in the body and exposure time.Pharmacological toxicity is evident when the therapeutic effects of drugs overshoot into adverse reactions in a predictable, dose-dependent manner. Central nervous system (CNS) depression from barbiturates is a classic example, with effects escalating from...
Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test01:22

Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test

In clinical practice, the direct measurement of hepatic blood flow to evaluate liver function presents significant challenges due to the intricate and specialized nature of the necessary techniques. Consequently, healthcare professionals often rely on empirical estimates derived from thorough patient examinations and liver function tests to gauge liver health. Among the tools at their disposal, the Child–Pugh and MELD scoring systems stand out for their ability to categorize and assess the...
Effect of Hepatic Disease on Pharmacokinetics: Drug Dosing and Hepatic Blood Flow01:26

Effect of Hepatic Disease on Pharmacokinetics: Drug Dosing and Hepatic Blood Flow

Chronic liver disease significantly impacts drug metabolism due to alterations in hepatic blood flow and enzyme accessibility. This disruption affects the body's pharmacokinetics—the movement and processing of drugs within the system. Key enzymes crucial for metabolizing medications become less accessible, changing how drugs are processed and utilized. Furthermore, liver disease influences the synthesis of plasma proteins, such as albumin and globulins, which play critical roles in drug binding...
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase01:27

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...
Drug toxicity: Drug–Drug Interaction01:30

Drug toxicity: Drug–Drug Interaction

Drug–drug interactions can precipitate toxicity through multiple mechanisms. Absorption interactions alter how drugs enter the body, exemplified when ranitidine increases the absorption of basic drugs, while cholestyramine decreases the levels of propranolol. Protein binding interactions occur when drugs share the same binding sites on plasma proteins. Drugs like aspirin and warfarin, when bound in excess, can lead to increased free drug concentrations, enhancing the potential for...
Drug Toxicity: Overview01:00

Drug Toxicity: Overview

Drug toxicity quantifies the harm a compound causes to an organism, varying by dose and potentially impacting whole systems or specific organs like the liver. Toxic reactions may arise from venomous insect or spider bites, with effects ranging from mild symptoms to severe outcomes such as brain damage or death. Common forms of acute poisoning include ethanol intoxication and overdose of pain or fever medications, with substances like GHB and heroin being particularly lethal at doses close to...