Giving African patients initiating AIDS drug treatment a commonly prescribed, inexpensive antibiotic significantly reduced their risk of death, new research shows.

The study followed 3,179 people in Uganda and Zimbabwe with CD4 counts less than 200 cells per microliter who were started on course of antiretroviral treatment (ART). Among those given co-trimoxazole - marketed as Bactrim, Septrim, and other brands - the risk of dying during the first three months fell by 59 percent compared to those who were not taking the antibiotic. Co-trimoxazole is commonly used to treat pneumonia and urinary tract and ear infections, and also has been found to have some anti-malarial properties.

At 72 weeks, the reduced mortality risk still persisted, though it evened out to 35 percent overall. In addition, treatment with co-trimoxazole cut frequency of malaria by 26 percent.

These benefits, combined with very low side effects, indicate that doctors in Africa should prescribe co-trimoxazole in addition to ART, according to the study. "Co-trimoxazole prophylaxis (combined with anti-HIV treatment) is cost-effective and has a substantial public health effect," said the investigators.

"Our results reinforce [World Health Organization] guidelines and provide strong motivation for provision of co-trimoxazole for at least 72 weeks to all adults starting combination ART in Africa," the investigators concluded.

The study, "Daily Co-trimoxazole Prophylaxis in Severely Immunosuppressed HIV-Infected Adults in Africa Started on Combination Antiretroviral Therapy: An Observational Analysis of the DART Cohort," was published early online in The Lancet (2010;doi:10.1016/S0140-6736(10)60057-8).