DAPSONE PYRIMETHAMINE MAY PREVENT MYCOBACTERIAL DISEASE IN IMMUNOSUPPRESSED PATIENTS INFECTED WITH THE HUMAN-IMMUNODEFICIENCY-VIRUS

Dapsone exhibits activity against Mycobacterium tuberculosis and Mycob acterium avium complex (MAC) in vitro. We retrospectively examined the incidence of mycobacterial diseases within a randomized prospective t rial of prophylaxis for Pneumocystis carinii pneumonia and toxoplasmos is. Of 501 participants who had not previously had a mycobacterial dis ease, 274 received dapsone/pyrimethamine (200/75 mg once weekly) and 2 27 received aerosolized pentamidine (300 mg once every 4 weeks). The m edian CD4 lymphocyte count was 113/mu L, and the median duration of tr eatment was 369 days. Six cases of tuberculosis, 22 of MAC infection, and 3 of Mycobacterium genavense disease occurred during treatment. St ratified by baseline CD4 lymphocyte counts, the annual product-limit i ncidence of mycobacterial disease was 5% during treatment with dapsone /pyrimethamine vs. 12% during treatment with aerosolized pentamidine f or patients whose counts were 0-24/mu L, 0 vs, 12% for those whose cou nts were 25-49/mu L, and 7% vs. 9% for those whose counts were 50-99/m u L. Adjusted for CD4 lymphocyte counts at start of treatment, the rel ative risk for patients receiving dapsone/pyrimethamine was 0.47 (95% confidence interval, 0.19-1.16; P =.10). This inexpensive and simple r egimen may prevent mycobacterial diseases and warrants further investi gation as a means of prophylaxis for multiple opportunistic diseases.