Prenatal drug therapy reduces HIV drug resistance

In pregnant women infected with HIV, a single dose of tenofovir and emtricitabine administered at delivery as an adjunct to nevirapine results in reduced resistance to non-nucleoside reverse transcriptase inhibitors 6 weeks after delivery, according to study findings published online Nov. 7 in The Lancet.

Benjamin H. Chi, MD, of the Centre for Infectious Disease Research in Zambia in Lusaka, Zambia, and colleagues conducted a study of 400 HIV-infected pregnant women of whom 200 were randomized to receive a single oral dose of 300-mg of tenofovir disoproxil fumarate with 200 mg of emtricitabine, while 199 received no drug.

Six weeks after delivery, women in the intervention group were 53% less likely to have resistance to non-nucleoside reverse transcriptase inhibitors. In both groups there were four cases of anemia. Serious adverse events among infants occurred in 10% of the intervention group and 12% of the control group, none of which were attributed to the intervention.

"Despite its effectiveness, this intervention might need modification to achieve the optimum protective effect," the authors write. "Nevertheless, it is an important adjunct to regimens that incorporate intrapartum nevirapine and should be considered in settings where drug combinations to be taken over several days might be impractical for patients or for the local health infrastructure," they conclude.

Chi BH, Sinkala M, Mbewe F, et al. Single-dose tenofovir and emtricitabine for reduction of viral resistance to non-nucleoside reverse transcriptase inhibitor drugs in women given intrapartum nevirapine for perinatal HIV prevention: an open-label randomised trial. Lancet. 2007;370:1698-1705.