Inclusion Criteria

Concurrent Medication:

Recommended:

• Prophylaxis for Pneumocystis carinii pneumonia.

Allowed:

• Aerosol ribavirin for short-term treatment of acute respiratory syncytial virus (RSV).
• Immunization according to the current recommendations of the Advisory Committee for Immunization Practice.
• IVIG. Systemic ketoconazole, acyclovir, or oral nystatin for acute therapy.

Patients must have the following:

• HIV infection. Patients with proven resistance to AZT are also eligible.

Prior Medication:

Allowed:

• Aerosol ribavirin.

Required:

Cohort C treatment:

• Stable prescribed dose of zidovudine (AZT) >= 90 mg/m2 for at least 6 weeks prior to study entry.

Exclusion Criteria

Co-existing Condition:

Patients with the following conditions or symptoms are excluded: AIDS or class P-2B, D, or E symptomatic infection.

Concurrent Medication:

Excluded:

• Hepatotoxic or neurotoxic drugs, immunosuppressants, or antiseizure medication. Ketoconazole, fluconazole, and acyclovir for prophylaxis. Immunomodulators (other than IVIG). Experimental drugs.

Cohort A patients:

• AZT for clinical indications.

Prior Medication:

Excluded:

• Other antiretroviral agents (including didanosine (ddI), dideoxycytidine (ddC), or soluble CD4) within 1 month of study entry. Systemic ribavirin administered for retroviral therapy within 2 months of study entry.
• Immunomodulating agents including interferon, isoprinosine, interleukin-2, or lymphocyte transfusions within 4 weeks of study entry.
• RBC transfusion within 4 weeks prior to study entry.

Alcohol or drug abuse.