Nevirapine is widely used to help prevent mother-to-child transmission of the HIV virus. In cases where the infants are nonetheless infected with HIV virus at birth, the standard treatment is to use protease inhibitors (PI) to reduce the amount of virus in their bloodstream. A new study involving 195 infants in South Africa found that children who were treated with PI and then switched to nevirapine were more likely to maintain virus below the detection threshold of the test than infants who continued to receive PI. Results of the study are available in the September 8 issue of JAMA.
Nevirapine has the additional advantage of being less costly than PI-an important benefit particularly in the under-resourced nations of sub-Saharan Africa. Moving away from PI-based regimens could offer other advantages as well: the unpleasant taste of protease inhibitors makes it more difficult for parents to ensure that children receive their medications every day, and there are concerns about metabolic toxicities with long-term use during critical periods of child development.
"Our results suggest that a majority of nevirapine-exposed children who are successfully treated with protease inhibitors could benefit from being switched to nevirapine. The switch regime is easier for the child and his or her parents to adhere to and would also save money," says senior author Louise Kuhn, PhD, professor of epidemiology at Columbia University's Mailman School of Public Health and the Gertrude H. Sergievsky Center, Columbia College of Physicians and Surgeons.
The trial was conducted between April 2005 and May 2009 at a hospital in Johannesburg. All 195 participating children had received the standard PI therapy of ritonavir-boosted lopinavir, stavudine, and lamivudine and had achieved viral suppression of less than 400 copies/mL for 3 or more months. A control group of 99 children continued to receive this therapy, while 96 others were switched to nevirapine. Children were followed up for 52 weeks after randomization.
Researchers found that children switched to nevirapine were more likely to maintain virus below the detection threshold of the test than infants who continued to receive PI. Children in the control group were more likely to have virus levels of 50 copies/mL or higher (58%) than children in the switch group (44%). However, children in the switch group were more likely to develop a high viral load of 1,000 copies/mL-a result associated with poor adherence to the drug regimen or drug-resistance before treatment.
While evidence suggests that switching children to nevirapine is generally a good strategy following successful treatment with PI, the researchers emphasized this should only be done with adequate monitoring of virus levels. "Although the value of virologic monitoring in HIV treatment is strongly emphasized in well-resourced settings, most programs in low-resource settings do not include it as part of routine services because of cost. Simple algorithms could be developed for targeted virologic testing to safely implement the switch strategy," the authors conclude.
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