Prophylaxis of Mycobacterium avium complex bacteremia in patients with AIDS.

Prevention of opportunistic infections is an integral part of caring for patients infected with human immunodeficiency virus. Mycobacterium avium complex (MAC) bacteremia can cause severe morbidity and excess mortality among these patients. Controlled trials of rifabutin for the prophylaxis of MAC bacteremia have been completed. Rifabutin reduced the incidence of MAC bacteremia by approximately one-half and, when disseminated disease due to MAC (DMAC) did develop, reduced the frequency of associated clinical symptoms. Moreover, prophylaxis with rifabutin was well tolerated. Prophylaxis of MAC bacteremia with macrolide antibiotics is currently being investigated, but no data from large-scale prospective trials are yet available. On the basis of trials completed thus far, the U.S. Public Health Service has recently recommended the use of rifabutin (300 mg/d) as prophylaxis for MAC bacteremia in patients with fewer than 100 CD4+ lymphocytes/mm3. The widespread use of this prophylactic regimen could reduce the rates of morbidity and mortality caused by DMAC. However, rifabutin must be administered only after careful consideration of the circumstances of individual patients. Potential drug interactions, cost, and compliance are important factors in the decision about which patients should receive prophylaxis.