Study Compares Antiretroviral Treatments Among HIV-Positive Mothers Who Received Nevirapine During Labor

A recent review of a clinical study funded by NIH comparing antiretroviral treatment regimens that contained either nevirapine or ritonavir-boosted lopinavir found that ritonavir/ lopinavir is more effective than nevirpaine among HIV-positive women who previously took a single-dose of nevirapine to prevent mother-to-child HIV transmission, South Africa's Business Day reports (Kahn, Business Day, 11/6). The study, called Optimal Combination Therapy after Nevirapine Exposure, has two purposes: to determine which of the two antiretroviral regimens is more effective for women who previously took single-dose nevirapine to prevent MTCT; and to examine whether taking single-dose nevirapine to prevent MTCT during labor subsequently compromises the effectiveness of nevirapine as a component of therapy for HIV-positive mothers (NIAID bulletin, 1028).

The study included 745 women in seven African countries and compared two antiretroviral regimens -- nevirapine, emtricitabine and tenofovir, or lopinavir-boosted ritonavir, emtricitabine and tenofovir -- in women who received nevirapine during labor and those who did not. According to Business Day, a routine interim review of the trial by an independent data safety monitoring board on Oct. 6 found that women who had nevirapine-resistant strains of HIV fared better if they were put on a regimen that did not contain the drug. Thirty-eight percent of the women who had developed resistance and were treated with a nevirapine-based regimen either died or failed to suppress the virus, while all of the women who had nevirapine-resistant strains of HIV but received a regimen containing lopinavir-boosted ritonavir were alive and suppressing the virus.

Francesca Conradie, a researcher from the University of the Wiwatersrand Clinical HIV Research Unit, said, "I'm not saying nevirapine should not have been given to these women -- it was the best we had at the time. What we can do now is protect nevirapine (to ensure it can be safely used in their subsequent treatment)," she said. According to Conradie, women who received nevirapine during childbirth and are now being treated with nevirapine-based regimen should be closely monitored to make sure the drugs are effectively suppressing HIV. They also should be switched to Kaletra -- known generically as lopinavir/ritonavir -- if they show signs of resistance, she said. "The longer you leave them on a failing regimen, the greater the risk that they will become resistant to all the drugs they are taking," Conradie added.

Business Day reports research is continuing into the efficacy of nevirapine and lopinavir-boosted ritonavir in women with no prior exposure to nevirapine (Business Day, 11/6).