The effect of acetaminophen on zidovudine metabolism in HIV-infected patients.

The concomitant administration of acetaminophen to HIV-positive patients receiving zidovudine (AZT) therapy has previously been thought to increase the likelihood of the toxicity of AZT due to increased serum levels, resulting from hypothesized metabolic competition. We measured serum AZT and metabolite levels by HPLC in HIV-infected patients taking regular doses of AZT with and without acetaminophen administration. In all patients, serum levels of AZT and the glucuronidated metabolite (GAZT) were similar with and without acetaminophen administration. AZT serum levels were not increased (p less than 0.05). We believe that the rationale for withholding acetaminophen from patients receiving AZT should be re-evaluated.