Inclusion Criteria

Concurrent Medication:

Allowed:

• Recombinant erythropoietin and/or G-CSF for AZT-related bone marrow suppression.
• Antibiotics other than metronidazole.
• PCP prophylaxis.
• Regularly prescribed medications such as antipyretics, analgesics, allergy medicine, and oral contraceptives.
• Vitamins and herbal therapies.

Concurrent Treatment:

Allowed:

• Acupuncture.
• Visualization techniques.

Patients must have:

• Documented HIV infection.
• CD4 count 100-300 cells/mm3.
• At least 3 consecutive months of prior AZT at a dosage of 500-600 mg bid, but with 5 weeks of antiretroviral washout prior to study entry.
• Consent of parent or guardian if less than 18 years old.

Prior Medication:

Required:

• Prior AZT at 500-600 mg bid at any time.
• PCP prophylaxis during antiretroviral washout.

Allowed:

• Prior ddI and/or ddC.
• Prior recombinant erythropoietin and/or G-CSF for AZT-related bone marrow suppression.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Chronic pancreatitis.
• Psychological conditions that would affect compliance.
• Intolerance to 500-600 mg/day AZT.
• Concurrent participation on another antiretroviral research treatment study (study treatment for opportunistic infection or complications of HIV is allowed).
• Considered likely to be noncompliant on study.

Concurrent Medication:

Excluded:

• Immunomodulators such as systemic corticosteroids, thalidomide, or cytokines.
• Rifabutin.
• Disulfiram (Antabuse) or other medications with similar effects, including metronidazole.
• Other drugs contraindicated with ritonavir.

[AS PER AMENDMENT 8/27/96: Immunization must be avoided during the antiretroviral washout period.]

Patients with the following prior conditions are excluded:

• Active opportunistic infection or febrile illness with temperature >= 38.5 C within 3 days prior to study entry.
• History of acute pancreatitis within the past 2 years.

Prior Medication:

Excluded:

• Prior 3TC or a protease inhibitor.
• Experimental drugs except those for HIV-related conditions, within the past 30 days.

[AS PER AMENDMENT 8/27/96: Immunization must be avoided prior to the antiretroviral washout period.]

Active substance abuse.