Open-Label Escalating Multiple-Dose Study of the Safety, Tolerance, and Pharmacokinetics of Oral U-90152 in HIV-1 Infected Males and Females With CD4 Counts of 200 - 500 Cells/mm3 Who Are Maintained on a Stable Dose of Zidovudine (AZT)

To evaluate the pharmacokinetics, safety, and tolerance of delavirdine mesylate ( U-90152 ) after multiple doses given orally to asymptomatic HIV-1 positive patients who are maintained on a stable dose of zidovudine ( AZT ). To investigate the optimum dose regimen of U-90152 that gives average trough concentrations > 1 micromolar in combination with standard AZT therapy, and to examine drug interactions between the two drugs. To establish the MTD of U-90152 in HIV-1 positive patients on stable AZT therapy. To investigate comparative pharmacokinetics between HIV-1 positive men and women.