The Safety and Effectiveness of Lamivudine Plus Stavudine or Zidovudine in HIV-Infected Patients Who Have Taken Zidovudine

Inclusion Criteria Patients must have: * At least six months of prior cumulative ZDV therapy. * Qualifying plasma HIV RNA count of \>= 4 log10 copies/ml obtained within 2 weeks of randomization. Exclusion Criteria Co-existing Condition: Patients with any of the following symptoms or conditions are excluded: * Presence of newly diagnosed AIDS defining opportunistic infection requiring acute therapy at time of enrollment. * Intractable diarrhea (\>= 6 loose stools/day for \>= 7 consecutive days). * Signs and symptoms of bilateral peripheral neuropathy \>= grade 2 at the time of screening. * Inability to tolerate oral medication. * Any other clinical conditions that in the opinion of the investigator, would make the patient unsuitable for study or unable to comply with the dosing requirements. Concurrent Medication: Excluded: * Therapy with agents with systemic myelosuppressive, neurotoxic pancreatotoxic, hepatotoxic or cytotoxic potential. * Therapy with rifampin, rifabutin, terfenadine, astemizole, cisapride, triazolam, midazolam and ketoconazole at any time while on indinavir therapy. Patients with any of the following prior conditions or symptoms are excluded: * History of acute or chronic pancreatitis. * Prior history of bilateral peripheral neuropathy. * Intractable diarrhea (\>= 6 loose stools/day for \>= 7 consecutive days) within 30 days prior to study entry. Prior Medication: Excluded: * Any prior antiretroviral therapy except for ddI, ddC, 3TC or ZDV (for ZDV, as specified in inclusion criteria). * Previous therapy with agents with significant systemic myelosuppressive, neurotoxic pancreatotoxic, hepatotoxic or cytotoxic potential within 3 months of study start. * Therapy with rifampin, rifabutin, terfenadine, astemizole, cisapride, triazolam, midazolam and ketoconazole within 2 weeks prior to starting indinavir. * Any other prior therapy that, in the opinion of the investigator, would make the patient unsuitable for study or unable to comply with the dosing regimen. Risk Behavior: Excluded: * Active alcohol abuse, sufficient in the investigator's opinion, to prevent compliance with study therapy or to increase the risk of developing pancreatitis. Required: At least 6 months of prior cumulative ZDV therapy.