Acetaminophen does not impair clearance of zidovudine

Ann Intern Med. 1991 Jun 1;114(11):937-40. doi: 10.7326/0003-4819-114-11-937.


Objective: To determine whether concurrent treatment with acetaminophen and zidovudine impairs clearance of zidovudine, thereby increasing the risk for zidovudine-induced hematologic toxicity.

Design: Dose escalation, drug interaction study.

Setting: University clinical research center.

Patients: Patients with the acquired immunodeficiency syndrome (AIDS) or advanced AIDS-related complex.

Interventions: Acetaminophen and 200 mg of zidovudine simultaneously every 4 hours. For 13 patients, the unit dosage of acetaminophen was 325 mg for 3 days; for 8 patients, the dosage was 650 mg for 3 days; and, for 6 patients, the dosage was 650 mg for 7 days.

Measurements: Zidovudine clearance and production of the glucuronide conjugate of zidovudine were assessed after acetaminophen treatment.

Main results: Neither zidovudine clearance nor production of the glucuronide conjugate of zidovudine was impaired after treatment with acetaminophen. Clearance of zidovudine was actually accelerated by 5%, 11%, and 33% with the three acetaminophen regimens, respectively (P = 0.002 by analysis of variance; P = 0.04 for linear trend when changes in the area-under-the-curve for zidovudine were compared).

Conclusion: Because serum concentrations of zidovudine decrease after the coadministration of acetaminophen, a pharmacokinetic interaction between zidovudine and acetaminophen is unlikely to increase the risk for hematologic toxicity associated with zidovudine.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AIDS-Related Complex / drug therapy
  • Acetaminophen / pharmacology*
  • Acquired Immunodeficiency Syndrome / drug therapy
  • Adult
  • Analysis of Variance
  • Drug Interactions
  • Half-Life
  • Humans
  • Metabolic Clearance Rate / drug effects
  • Middle Aged
  • Zidovudine / blood
  • Zidovudine / pharmacokinetics*


  • Acetaminophen
  • Zidovudine