Quadrupledrug therapy for Mycobacterium avium-intracellulare bacteremia in AIDS patients

The mycobacterial response was evaluated for patients with Mycobacterium avium-intracellulare complex (MAC) bacteremia treated with a quadruple regimen of rifabutin, clofazimine, isonia-zid, and ethambutol. Mycobacteremia was cleared in 22 of 25 patients who received this regi-men, and 18patients experienced complete resolution of symptoms associated with MACinfection. All of the patients were immunodeficient, with a mean CD4 cell count at the time of diagnosis of MAC infection of 54.7 ± 54.6 cells/sf, All MAC isolates were resistant to clofazimine, isonia-zid, and ethambutol. Sixteen of 24 isolates were resistant to rifabutin. Improved results of treat-ment may be related to the use of a higher dose of rifabutin (300-600 mg/day) compared with other studies (150-300 mg/day), earlier diagnosis and institution of treatment, and synergy be-tween rifabutin and ethambutol. The quadruple regimen used in this study appears effective in clearing mycobacteremia and in ameliorating symptoms of infection. Mycobacterium avium-intracellulare complex (MAC) is a common opportunistic pathogen in patients with AIDS. It was found in 60%of AIDS patients autopsied at Memorial Sloan Kettering Cancer Center [1] and has been cultured during lif