Fluconazole and Enhanced Effect of Rifabutin Prophylaxis: Letter

To the Editor: The results of two double-blind, randomized, placebo-controlled trials published in the Journal (Sept. 16 issue)1 have shown that prophylactic treatment with rifabutin (300 mg per day) significantly reduces the incidence of Mycobacterium avium complex bacteremia. A Special Report in the same issue2 further recommends rifabutin prophylaxis in adults and adolescents with human immunodeficiency virus infection and CD4+ counts of 100 cells or less per cubic millimeter and suggests that effective primary prophylaxis could improve the patients' quality of life and survival. [...]daily doses of more than 300 mg of rifabutin may prove more effective in the prevention of disseminated M. avium complex disease but should not be used until the safety and efficacy are confirmed in clinical trials.