WEDNESDAY, Jan. 10, 2007 (HealthDay News) -- A new U.S. study says that delaying the use of the drug nevirapine for at least six months after HIV-infected women give birth may improve treatment outcomes in women who took nevirapine during labor to prevent their babies from becoming infected with HIV.
The findings could lead to changes in the treatment of millions of mothers infected with HIV, the virus that causes AIDS. The study is published in the Jan. 11 issue of The New England Journal of Medicine.
Nevirapine -- used alone or in combination with other drugs -- significantly reduces the risk that a pregnant women infected with HIV will pass the virus to her child at birth. However, previous research has found that 20 percent to 69 percent of women who receive a single dose of nevirapine during labor go on to develop resistance to the drug.
This resistance may affect a woman's ability to respond to nevirapine-containing antiretroviral therapy (ART) when they may need it to save their lives, according to background information in the study. In most parts of the world, nevirapine is the cornerstone of three-drug ART.
This study, by researchers at the Harvard School of Public Health and Brigham and Women's Hospital in Boston, included 218 HIV-infected women who received a single dose of nevirapine or a placebo during labor, along with a short course of the antiretroviral drug zidovudine (AZT) during pregnancy.
Sixty of the women started nevirapine-based ART within six months of giving birth, while the rest of the women started the treatment six months after labor. Among the 60 women who started ART within six months after labor, treatment failure occurred in 41.7 percent of those who received a single dose of nevirapine during labor, compared to 0 percent among those who received the placebo.
Among the women who began nevirapine-based ART six months after giving birth, treatment failure rates were about the same for women who received either nevirapine or placebo during labor.
"These results translate into very clear policy for how to treat AIDS in new mothers who received nevirapine to protect their infants. If you can wait six months to administer nevirapine-based ART, do so. If not, treat only with combinations of drugs that do not contain nevirapine or nevirapine-related drugs. Implementing this policy can improve the health of women who need AIDS treatment," study co-author Max Essex, chairman of the Harvard School of Public Health AIDS Initiative, said in a prepared statement.
The New Mexico AIDS Education and Training Center has more about HIV and pregnancy.