Inclusion Criteria

Concurrent Medication:

Allowed:

• Primary or secondary PCP prophylaxis with TMP/SMX, dapsone, or aerosolized pentamidine.
• Any approved therapy for antiretroviral treatment, or antiretroviral therapy available through FDA-sanctioned treatment IND or treatment protocol.

Patients must have:

AMENDED (PART B):

• Either HIV infection OR no HIV infection.
• CD4 count unspecified.

ORIGINAL:

• Documented HIV infection.
• CD4 count < 200 cells/mm3 within 90 days prior to study entry.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms and conditions are excluded:

• Known Mycobacterium avium-intracellulare (MAI) bacteremia or presence of a clinical syndrome compatible with MAI (i.e., fevers, weight loss, elevated LDH and alkaline phosphatase).
• Fever = or > 38.5 deg C (100.4 deg F) within 7 days prior to study entry.

Concurrent Medication:

Excluded:

• Acute or chronic use of phenobarbital, carbamazepine, rifampin, dilantin, fluconazole, itraconazole, ketoconazole, ciprofloxacin, beta-blockers, or clarithromycin.
• Oral contraceptives.
• Acute therapy for an AIDS-related opportunistic infection or malignancy, or other acute medical illness, or infection.
• Maintenance therapy for CMV, cryptococcal meningitis, or toxoplasmosis.
• Cytotoxic chemotherapy.

Patients with the following prior conditions are excluded:

• History of intolerance or hypersensitivity to study drugs, other macrolide antibiotics, or rifampin.
• Three or more loose bowel movements per day within 3 months prior to study entry.
• Unintentional weight loss >= 5 percent of body weight within 3 months prior to study entry.

Prior Medication:

Excluded:

• Rifabutin within 30 days prior to study entry.
• Clarithromycin or azithromycin within 14 days prior to study entry.
• Acute therapy for an AIDS-related opportunistic infection or malignancy, or other acute medical illness, or infection within 28 days prior to study entry.

Prior Treatment:

Excluded:

• Blood transfusions within 1 month prior to study entry.