Rifabutin in combination with clofazimine, isoniazid and ethambutol in the treatment of AIDS patients with infections due to opportunist mycobacteria

96 AIDS patients with fever and either acid-fast bacilli on microscopic examination of bacteriological samples or mycobacteria isolated by culture were treated with a daily 4-drug combination of 7–10 mg/kg rifabutin, 5 mg/kg isoniazid, 20 mg/kg ethambutol and 100 mg clofazimine.

46 patients were excluded from efficacy assessment: 13 died before or within the first days of treatment, 5 had negative initial cultures, 14 had initial cultures positive for M. tuberculosis, 4 for M. kansasii, 1 for M. flavescens, 1 for M. gordonae, 7 were lost to follow-up and 1 received no rifabutin.

In the 50 remaining patients, 31 had disseminated disease due to M. avium intracellulare complex (MAIC) and 19 had apparently localised disease, due to MAIC in 15 cases and to M. xenopi in 4 cases. Side-effects led to withdrawal of isoniazid in 1 case (hepatic enzymes increased) and rifabutin in another (thrombocytopenia). After 1 month of treatment, fever decreased from 38.4 ± 0.6 °C to 37.7 ± 0.5 °C (p < 0.01) and patients stopped losing weight. After 3 months treatment, only 37 patients were alive and still under treatment. Cultures became negative in 16 of 23 patients with available bacteriological data (9 of 14 patients with disseminated disease and 7 of 9 patients with localised disease), relapse occurred before death in 4 patients. 34 patients died before treatment was completed. Death was considered to be related to mycobacterial infection in 5 cases.

We conclude that the 4-drug combination is safe and, in some cases, it appears to be effective.