Inclusion Criteria

Concurrent Medication:

Allowed:

• Any antiretroviral therapy that is approved or is available through an FDA-sanctioned treatment IND or treatment protocol.
• Primary or secondary PCP prophylaxis with TMP/SMX, dapsone, or aerosolized pentamidine, as well as approved therapies for other AIDS-related opportunistic infections not otherwise excluded.
• Erythromycin, interferon-alpha, and supportive care for any therapy-related toxicities as necessary.

Patients must have:

• HIV infection.
• Confirmed MAC bacteremia.
• Consent of parent or guardian if less than 18 years of age.

Exclusion Criteria

Concurrent Medication:

Excluded:

• MAC inhibitors, including aminoglycosides, quinolones, clofazimine, azithromycin (except when administered as a substitute drug), and rifamycins, during the first 24 weeks of the study.
• Immunomodulators (including colony-stimulating cytokines such as GM-CSF and G-CSF) other than those that are specifically allowed.
• Steroids in excess of physiologic replacement doses.
• Cytotoxic chemotherapy.

Patients with the following prior conditions are excluded:

• History of treatment-limiting intolerance or hypersensitivity to the study drugs or other macrolides.
• Changes on chest radiograph within 7 days prior to study entry, that are consistent with acute Pneumocystis carinii pneumonia, pulmonary tuberculosis, or other acute respiratory infection.

Prior Medication:

Excluded:

• Clarithromycin, azithromycin, or ethambutol for more than 10 consecutive days within the 8 weeks prior to study entry OR between the time an initial AFB positive blood sample was collected and study entry.
• Cytokines (other than erythropoietin and interferon-alpha) within 8 weeks prior to study entry.
• Steroids within 8 weeks prior to study entry.
• Cytotoxic chemotherapy within 8 weeks prior to study entry.
• Acute therapy for an AIDS-related opportunistic infection or malignancy, or other acute medical illness or infection within 4 weeks prior to study entry.
• Rifabutin monotherapy if initiated for MAC prophylaxis between the time an initial AFB positive blood sample was collected and study entry.
• Aminoglycosides, quinolones, clofazimine, or rifamycins IF ADMINISTERED IN ANY COMBINATION within 7 days prior to study entry OR between the time an initial AFB positive blood sample was collected and study entry.