THE INDIVIDUAL MICROBIOLOGIC EFFECT OF 3 ANTIMYCOBACTERIAL AGENTS, CLOFAZIMINE, ETHAMBUTOL, AND RIFAMPIN, ON MYCOBACTERIUM-AVIUM COMPLEX BACTEREMIA IN PATIENTS WITH AIDS

The individual antibacterial activities of clofazimine, ethambutol, an d rifampin in the treatment of Mycobacterium avium complex bacteremia in patients with AIDS were determined. Sixty human immunodeficiency vi rus 1-infected patients who had at least one blood culture positive fo r M. avium complex were randomized to receive either clofazimine (200 mg), ethambutol (15 mg/kg), or rifampin (600 mg) once daily for 4 week s. Only ethambutol resulted in a statistically significant reduction i n the level of mycobacteremia. The median change in individual baselin e colony counts was -0.60 log(10) cfu/ml after 4 weeks of ethambutol ( P =.046). In contrast, median changes in individual baseline colony co unts were -0.2 log(10) cfu/ml and +0.2 log(10) cfu/ml for clofazimine and rifampin, respectively (both, P >.4). Ethambutol had greater antib acterial activity, as determined by changes in the level of mycobacter emia, than either rifampin or clofazimine, supporting its continued us e in combination with other agents in the treatment of M. avium infect ion.