Prospective Open-Label Study of the Emergence of Drug Resistance in Patients Infected With HIV-1 Who Are Taking Oral U-87201E

Inclusion Criteria Patients must have: * Enrollment on protocol RV-43 (AZT resistance study). * Development of a primary RV-43 study endpoint-opportunistic infection. * HIV isolate with an AZT IC50 \> 50 times that of the sensitive type strain. * Able to swallow tablets without difficulty. * Normal QTc interval on EKG. Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: * Clinically significant hypersensitivity to piperazine type drugs (Antepar, Stelazine). * Severe uncontrollable diarrhea or vomiting or known malabsorption. * Symptomatic hyperlipidemia. Concurrent Medication: Excluded: * Other experimental drugs. * AZT, ddI, ddC, foscarnet, immunomodulators or other agents with primary antiretroviral activity (exemptions by principal investigator permitted). Patients with the following prior conditions are excluded: History of clinically significant cardiovascular disease or nervous system or muscle disease, including seizures, peripheral neuropathy, dementia, or motor dysfunction. Prior Medication: Excluded: * Experimental drugs within 4 weeks prior to study entry.