Inclusion Criteria

Concurrent Medication:

Allowed:

• Prior antiretroviral agents for up to 6 months per agent.

Patients must have:

• HIV infection.
• Asymptomatic or mildly symptomatic.
• CD4 count 301 - 500 cells/mm3.

Exclusion Criteria

Co-existing Condition:

Patients with the following condition are excluded:

Unable or unwilling to comply with study procedures.

Concurrent Medication:

Excluded:

• Chemoprophylactic therapy for mycobacterial infection.
• Any nonstudy prescription medications without approval of investigator.

Patients with the following prior conditions are excluded:

• History of grade 3 or 4 toxicity to <= 600 mg/day AZT.
• History of intolerance to lactose.
• Chronic diarrhea within 6 months prior to study entry.
• Unexplained intermittent or chronic fever, defined as temperature >= 38.5 C for any 7 days within the 30 days prior to study entry.

Prior Medication:

Excluded:

• Antiretroviral therapy within 2 weeks prior to study entry.
• Prior HIV vaccines.
• Biological response modifiers within 30 days prior to study entry.
• Prior foscarnet.
• Any investigational drug with a washout < 5 half-lives prior to study entry.
• Any medications known to alter renal, hepatic, or hematologic / immunologic function (such as barbiturates, phenothiazines, cimetidine, immunomodulators, etc.) within 14 days prior to study entry.

Recent history of alcohol and/or drug abuse.