Pharmacokinetics of zidovudine in HIV-positive patients with liver disease.

The pharmacokinetics of zidovudine (ZDV) have been studied in eight AIDS patients with normal liver function, and in four AIDS patients with liver disease. Patients who were previously untreated with ZDV were given 250 mg ZDV, and plasma levels of ZDV and its glucuronic metabolite, GZDV, were determined at 0.5, 1, 1.5, 2, 3, and 4 hours after the dose. In patients with liver disease, Cmax and AUC of ZDV were higher, the oral clearance was only one-eighth that of patients without liver disease, and the elimination half-life was longer. There was a trend for concentrations of the principal metabolite, GZDV, to be lower in patients, and, therefore, the ratio of the AUC for GZDV to that for ZDV was much lower in patients with liver disease. Therefore, HIV-seropositive patients with liver disease had the same markedly altered disposition of ZDV as seronegative patients with liver disease. Although this therapy was not clearly associated with a higher incidence of toxicity, some patients with liver disease had to discontinue therapy because of intolerance; therefore, plasma levels of these patients should be monitored when such therapy is undertaken.