Activated charcoal reduces the need for N-acetylcysteine treatment after acetaminophen (paracetamol) overdose

J Toxicol Clin Toxicol. 1999;37(6):753-7. doi: 10.1081/clt-100102452.


Background: The evidence for efficacy of gastric lavage and activated charcoal for gastrointestinal decontamination in poisoning has relied entirely on volunteer studies and/or pharmacokinetic studies and evidence for any clinical benefits or resource savings is lacking.

Aim of study: To investigate the value of gastrointestinal decontamination using gastric lavage and/or activated charcoal in acetaminophen (paracetamol) poisoning.

Patients and methods: We analyzed a series of 981 consecutive acetaminophen poisonings. These patients were treated with gastric lavage and activated charcoal, activated charcoal alone, or no gastrointestinal decontamination. The decision as to which treatment was received was determined by patient cooperation, the treating physician, coingested drugs, and time to presentation after the overdose.

Results: Of 981 patients admitted over 10 years, 10% (100) had serum concentrations of acetaminophen that indicated a probable or high risk of hepatotoxicity. The risk of toxic concentrations for patients ingesting less than 10 g of acetaminophen was very low. In patients presenting within 24 hours, who had ingested 10 g or more, those who had been given activated charcoal were significantly less likely to have probable or high risk concentrations (Odds ratio 0.36, 95% CI 0.23-0.58, p < 0.0001). Gastric lavage, in addition to activated charcoal, did not further decrease the risk (Odds ratio 1.12, 95% CI 0.57-2.20, p = 0.86).

Conclusions: Toxic concentrations of serum acetaminophen (paracetamol) are uncommon in patients ingesting less than 10 g. In those ingesting more, activated charcoal appears to reduce the number of patients who achieve toxic acetaminophen concentrations and thus may reduce the need for treatment and hospital stay.

MeSH terms

  • Acetaminophen / pharmacokinetics
  • Acetaminophen / poisoning*
  • Acetylcysteine / therapeutic use*
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Charcoal / therapeutic use*
  • Drug Overdose / drug therapy*
  • Drug Therapy, Combination
  • Female
  • Gastric Lavage
  • Humans
  • Male
  • Middle Aged


  • Charcoal
  • Acetaminophen
  • Acetylcysteine