Abstract :
The treatment of disease caused by Mycobacterium avium complex (MAC) in HIV-infected individuals has undergone considerable evolution over the past 15 years. Agents with known antimycobacterial activity such as rifampin/rifabutin, ethambutol, and clofazimine, as well as others such as amikacin, liposome-encapsulated gentamicin, several of the fluoroquinolones (ciprofloxacin, ofloxacin, and sparfloxacin), and the new macrolides, azithromycin and clarithromycin, have all been used with varying degrees of success. Of all these agents, the macrolides have clearly had the biggest impact to date on the management of disseminated MAC. Studies of both azithromycin and clarithromycin in short-term monotherapy trials have corroborated their clinical and microbiological efficacy. The risk of drug resistance with monotherapy, however, has prompted investigation of combination regimens for the treatment of MAC. A recent study of a three-drug, clarithromycin-based regimen versus a four-drug regimen without clarithromycin has shown that patients treated with the regimen containing clarithromycin had significantly greater overall symptomatic improvement, more rapid and significant clearing of mycobacteremia, and improved survival. Results from studies of combination regimens with azithromycin should be available soon. Although there is still no “regimen of choice,” initial treatment with at least two active agents, one of which should be either azithromycin or clarithromycin, is the currently recommended approach; the majority opinion favors ethambutol as the preferred second agent. Use of adjunctive therapies and more potent antiretroviral regimens may also play a role
