A Study of Rifabutin, Used Alone or With Ethambutol in the Prevention of Mycobacterium Avium Complex (MAC) Bacteremia in Patients With AIDS
A Study of Rifabutin, Used Alone or With Ethambutol in the Prevention of Mycobacterium Avium Complex (MAC) Bacteremia in Patients With AIDS
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.
Inclusion Criteria

 Concurrent Medication:

 Required:

 -  AZT, d4T, ddI, or ddC.

 -  Antipneumocystis prophylaxis.

 Allowed:

 -  Short course (< 14 days) of ciprofloxacin for acute infections.

 Patients must have:

 -  AIDS.

 -  CD4 count <= 100 cells/mm3.

 -  NO prior or current MAC infection.

 Prior Medication:

 Required:

 -  Antipneumocystis prophylaxis for at least 4 weeks prior to study entry.

 Allowed:

 -  Prior rifabutin.

 -  Prior ethambutol.

 -  Prior clarithromycin.

 Exclusion Criteria

 Co-existing Condition:

 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.

 Concurrent Medication:

 Excluded:

 -  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.

 Prior Medication:

 Excluded within 4 weeks prior to study entry:

 -  Rifampin.

 -  Isoniazid.

 -  Clofazimine.

 -  Cycloserine.

 -  Ethionamide.

 -  Amikacin.

 -  Ciprofloxacin.