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.
Related Commentary
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.