To optimize Mycobacterium avium Complex (MAC) prophylaxis in AIDS patients by measuring
serum rifabutin levels and adjusting the dose accordingly. To combine rifabutin with
ethambutol to examine the effect of combination therapy in preventing or delaying the
incidence of MAC bacteremia in this patient population.
Patients are randomized to receive oral rifabutin alone or rifabutin/ethambutol daily for 12
months, with possible continuation of medicine lifelong. Doses will be adjusted to maintain
minimum blood levels of the drugs.
- AZT, d4T, ddI, or ddC.
- Antipneumocystis prophylaxis.
- Short course (< 14 days) of ciprofloxacin for acute infections.
Patients must have:
- CD4 count <= 100 cells/mm3.
- NO prior or current MAC infection.
- Antipneumocystis prophylaxis for at least 4 weeks prior to study entry.
- Prior rifabutin.
- Prior ethambutol.
- Prior clarithromycin.
Patients with the following symptoms or conditions are excluded:
- Positive tuberculin skin test (PPD > 5 mm).
- Active M. tuberculosis.
- Perceived as unreliable or unavailable for frequent monitoring.
- Other antiretrovirals not specifically allowed.
- All investigational drugs.
- Other antimycobacterial therapy, such as clarithromycin, azithromycin, rifampin,
clofazimine, amikacin, streptomycin, isoniazid, cycloserine, ethionamide, and
ciprofloxacin (>= 14 days).
Patients with the following prior conditions are excluded:
Known hypersensitivity to rifabutin, rifampin, or other rifamycins and/or ethambutol.
Excluded within 4 weeks prior to study entry: