A Study of Saquinavir and Zalcitabine, Used Alone and Together, in the Treatment of Advanced HIV Infection in Patients Who Stopped Taking or Who Cannot Take Zidovudine

Inclusion Criteria Concurrent Medication: Allowed: * G-CSF and erythropoietin. * Prophylaxis or chronic suppression/maintenance therapy with dapsone, aerosolized pentamidine, isoniazid, rifampin, fluoroquinolones, pyrazinamide, ethambutol, fluconazole, itraconazole, acyclovir, clotrimazole, nystatin, trimethoprim/sulfamethoxazole, pyrimethamine, folic acid, sulfadiazine, clindamycin, and fansidar. Concurrent Treatment: Allowed: * Limited localized radiation therapy to the skin. Patients must have: * Documented HIV infection. * CD4 count 50 - 300 cells/mm3. * Received prior AZT that has been discontinued at least 28 days prior to study entry. * No active opportunistic infection requiring immediate treatment. Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: * Signs or symptoms of peripheral neuropathy. * Malabsorption or inadequate oral intake (defined as unable to eat one or more meals daily because of chronic nausea, emesis, or abdominal/oral-esophageal discomfort. * Malignancy, visceral Kaposi's sarcoma, or lymphoma requiring systemic chemotherapy and/or radiotherapy within the next 48 weeks. * Any grade 3 or worse laboratory or clinical abnormality. * Inability to comply with protocol requirements. Concurrent Medication: Excluded: * Other antiretroviral drugs. * Experimental drugs. * Nephrotoxic or hepatotoxic drugs. * Drugs likely to cause peripheral neuropathy. * Antineoplastic agents. * Biologic response modifiers. Concurrent Treatment: Excluded: * Radiation therapy other than limited localized therapy to skin. Patients with the following prior conditions are excluded: * History of non-Hodgkin's lymphoma. * Unexplained fever \>= 38.5 C (101.5 F) persisting for 14 days or longer within the 28 days prior to study entry. * Unexplained, chronic diarrhea (defined as 3 or more loose stools daily) persisting for 14 days or longer within the 28 days prior to study entry. * History of grade 2 or worse peripheral neuropathy. Prior Medication: Excluded: * Prior HIV proteinase inhibitor. * Prior antiretroviral therapy other than AZT. * Acute therapy for opportunistic infection within 14 days prior to study entry. Prior Treatment: Excluded: * More than 3 units of blood in any 21-day period within 3 months prior to study entry. Required: * Prior AZT.