Prevention of disseminated Mycobacterium avium complex infection with reduced dose clarithromycin in patients with advanced HIV disease

Objective: To evaluate the ability of once daily reduced dose clarithromyci n to prevent disseminated Mycobacterium avium complex (dMAC) infection in p atients with advanced HIV disease. Design: Non-randomized, retrospective study. Setting: Outpatient clinic of an urban university-affiliated municipal hosp ital. Patients: A group of 192 HIV-infected patients with a CD4 count < 100 x 10( 6) cells/l who were followed for at least 90 days during a 6-year period (1 991-1996) before the use of protease inhibitors. Interventions: Clarithromycin 500 mg orally once daily (n = 84), rifabutin 300 mg orally once daily (n = 47) or no prophylaxis (n = 61). Main outcome measures: Positive blood culture for M. avium complex (MAC), t ime to development of dMAC, and time to death. Results: When compared with no prophylaxis or rifabutin, the incidence of d MAC and time to development of dMAC were improved among those patients rece iving clarithromycin (P < 0.001). Prolonged survival was associated with bo th clarithromycin and rifabutin use when compared with no prophylaxis (P < 0.002). In patients who failed prophylaxis, resistance to clarithromycin an d rifabutin was observed. Conclusions: In the era prior to protease inhibitor use, once daily clarith romycin at a dose of 500 mg was associated with a reduction in the incidenc e of dMAC, appeared to be superior to rifabutin, and was associated with pr olonged survival in patients with advanced HIV disease. (C) 1999 Lippincott Williams & Wilkins.