HIV-Positive Pregnant Women Who Receive Tenofovir, Emtricitabine During Childbirth Have Decreased Risk of Developing Drug Resistance, Study Says
HIV-positive women who are pregnant and receive the antiretrovirals tenofovir and emtricitabine during childbirth could reduce the risk of developing resistance to antiretroviral drugs, according to a study published Wednesday in the Lancet, AFP/Yahoo! News reports (AFP/Yahoo! News, 11/7).
For the study, Benjamin Chi of the University of Alabama-Birmingham and the Centre for Infectious Disease Research in Zambia randomly assigned 400 HIV-positive pregnant women who sought care at two clinics in Lusaka, Zambia, to take either a single dose each of tenofovir and emtricitabine or neither drug. The women all were offered nevirapine and short-course treatment with zidovudine, according to the study (Chi et al., Lancet, 11/7).
The standard treatment to prevent mother-to-child transmission is to provide a single dose of nevirapine during childbirth, which reduces the risk of HIV transmission by 40%. However, the drug increases infants' risk of contracting a drug-resistant strain of HIV if the virus is transmitted during birth. In addition, nevirapine increases the woman's risk of developing a drug-resistant strain of HIV (AFP/Yahoo! News, 11/7).
Women assigned to take tenofovir and emtricitabine during childbirth were 53% less likely than women in the control group to have developed drug resistance six weeks after delivery, the study found. Women in the tenofovir-emtricitabine group had a 12% chance of developing drug resistance, compared with a 25% risk for the control group.
Four women in each group experienced postpartum anemia, and 10% of infants in the tenofovir-emtricitabine group and 12% in the control group had adverse side effects, including septicemia and pneumonia, according to the study (Lancet, 11/7). The researchers said the side effects likely were not the result of the new drug combination.
Shahin Lockman and James McIntrye of the Harvard School of Public Health in a commentary accompanying the study said the findings "provide strong evidence that adding single-dose tenofovir-emtricitabine" to the standard method of preventing mother-to-child HIV transmission is a "new, effective and feasible approach to reducing maternal nevirapine resistance" (AFP/Yahoo! News, 11/7).
An abstract of the study is available online.