[Pharmacokinetics of 3'-azido-3 deoxy-thymidine (AZT) in a patient undergoing hemodialysis]

Zidovudine (AZT) is the only effective drug in the treatment of AIDS. No data are available on the pharmacokinetics of this drug in patients with end-stage renal disease (ESRD). We report on the pharmacokinetics of zidovudine between sessions of hemodialysis and during the procedure in one patient with ESRD. In 1987 a 40-year-old man with ESRD treated with hemodialysis had the AIDS-related complex. The T4/T8 ratio was 0.49. An enzyme-linked immunosorbent assay and Western Blot studies revealed IgG antibodies specifically directed against HIV. The patient was then treated with zidovudine (100 mg three times daily). Studies of the pharmacokinetics of the drug, conducted between hemodialysis sessions, were performed on days 1 and 14 after the start of zidovudine treatment. Paired arterial and venous blood samples were obtained simultaneously one hour after the start of a hemodialysis session on day 20. The peak and the trough concentrations of zidovudine were 0.61 and 0.15 microgram per milliliter, respectively. We observed a marked accumulation of the main metabolite of zidovudine, G-AZT, with a concentration of about 65 micrograms per milliliter on day 14. The half-life was 2.9 hours. The hemodialysis clearance of zidovudine and its metabolite were 102 and 71 ml per minute, respectively. The half-life of zidovudine was three times longer in our patient than in a normal subject.(ABSTRACT TRUNCATED AT 250 WORDS)