Nevirapine Inexpensive, Long-Lasting Option in Preventing Mother-to-Child HIV Transmission, Study Says
One dose of the antiretroviral drug nevirapine administered to an HIV-positive pregnant women during labor and her infant after birth could reduce the risk of vertical HIV transmission better than multi-dose treatment with zidovudine, potentially offering a "cheap, lasting shield to infants in poor countries who are at risk" of mother-to-child HIV transmission, according to a follow-up study published in the Sept. 13 issue of the Lancet, AFP/Yahoo! News reports. Johns Hopkins University and Ugandan researchers reexamined the participants of the HIVNET 012 study, which was conducted from 1997 to 1999, when the infants reached 18 months of age (AFP/Yahoo! News, 9/11). Preliminary results of the NIH-sponsored study comparing nevirapine with a short course of zidovudine were announced in July 1999 in Kampala, Uganda. Approximately 600 HIV-positive Ugandan women in their ninth month of pregnancy who had not taken antiretroviral therapy received either a short course of zidovudine -- a dose every three hours during labor, followed by twice-daily doses to newborns for one week following birth -- or a single nevirapine pill, with newborns also taking a single dose of the liquid form of the drug after birth. Nevirapine cut the risk of HIV transmission by nearly 50%, researchers found. Four months after birth, 13% of the infants receiving nevirapine tested positive for HIV, compared with 25% of infants receiving zidovudine (Kaiser Daily HIV/AIDS Report, 7/15/99).
After 18 months, 75 infants receiving zidovudine and 47 infants receiving nevirapine tested HIV-positive, according to the release (JHU release, 9/11). Researchers found that the risk of vertical HIV transmission was 15.7% for the nevirapine group at 18 months, compared with 25.8% for the infants who received zidovudine, AFP/Yahoo! News reports. The researchers concluded that the "simple, inexpensive, well-tolerated regimen [of nevirapine] has the potential to significantly decrease HIV-1 transmission in less-developed countries" (AFP/Yahoo! News, 9/11). Dr. Brooks Jackson, director of pathology at Johns Hopkins University School of Medicine and co-author of the study, said, "The use of nevirapine, if widely implemented, has the potential to prevent several hundred thousand new infections every year." He added, "This regimen is extremely simple, safe and inexpensive, but access to HIV testing and counseling remains a huge obstacle." Jackson also said that funding for HIV prevention and treatment programs in Africa will help, according to a JHU release (JHU release, 9/11). Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, which sponsored the study, said, "This landmark study could have far-reaching implications in resource-poor countries where breastfeeding and mother-to-child HIV transmission are both common. Indeed, the potential for lessening the burden of HIV/AIDS with this ... regimen makes this work a very important public health breakthrough" (NIH release, 9/11).
In an accompanying commentary, Dr. Karen Palmore Beckerman of the New York University School of Medicine Bellevue Hospital Center said that administering single-doses of nevirapine to pregnant women and infants could lead to an increase in drug-resistant HIV strains. According to Palmore Beckerman, "It would leave between 20% and 100% of the 3.2 million mothers who received prophylaxis and more than 50% of the remaining 554,000 infants infected and resistant to nevirapine and other nonnucleoside reverse transcriptase inhibitors -- the very agents on which success of antiretroviral therapy in resource-poor settings will hinge." Palmore Beckerman says that the recent WTO agreement that allows countries without domestic drug manufacturing to import generic versions of patented drugs in a health emergency could mean that antiretroviral drugs could be inexpensively "prepared in convenient single-pill triple combinations for once and twice daily dosing," according to Palmore Beckerman. Therefore, she says that "[s]uboptimum" single- and double-drug prophylaxis regimens "no longer have a justifiable place in the front lines of the global struggle against HIV/AIDS." Palmore Beckerman concludes, "It is up to all of us to focus on development of equitable distribution and effective use of these agents now. Once they are widely available, it may be too late" (Palmore Beckerman, Lancet, 9/13).