Part I: Five male patients enter a pharmacokinetic concentration-controlled trial of U-87201E plus zidovudine at the University of Rochester site only. A target plasma concentration range at trough for U-87201E will be determined. Pharmacokinetic monitoring continues for 7 days or until the desired dose regimen has been determined. The five patients may be eligible to continue in Part II of the study to complete a total of 12 weeks of therapy.