Infant-only HIV Prophylaxis Reduces Nevirapine Resistance

Use of infant-only single-dose nevirapine (NVP; Viramune) plus zidovudine (ZDV; Retrovir) not only prevents mother-to-child (MTCT) HIV transmission, but also reduces NVP resistance in mothers and infants, according to an article published in the February 15, 2006 issue of The Journal of Infectious Diseases.

These data were first presented in part at the XIV International HIV Drug Resistance Workshop, Quebec City, Canada, June 7-11, 2005 (Abstract 1).

The use of single-dose NVP to prevent MTCT has been associated with the development of NVP resistance in mothers and their infants who develop HIV infection despite preventive treatment with NVP.

Researchers at Johns Hopkins, Rutgers and the University of North Carolina at Chapel Hill, NC analyzed the emergence of NVP resistance in HIV positive infants in Malawi who received single-dose regimens of NVP for the prevention of MTCT of HIV.

All the infants received single-dose NVP and some also received zidovudine (ZDV; Retrovir). Mothers received or did not receive single-dose NVP based on when they came to the hospital for delivery.

NVP resistance developed less frequently in infants 6-8 weeks old when they received single-dose NVP plus ZDV and mothers had not received single-dose NVP than when infants had received single-dose NVP alone and mothers had received single-dose NVP.

In summary, among the 4 regimens studied by the researchers, not providing intrapartum single-dose NVP to mothers and providing single-dose NVP plus ZDV to infants was optimal in several respects: the development of NVP resistance in mothers was eliminated; the development of NVP resistance in infants was substantially less frequent, compared with that observed for all other regimens;

The authors conclude, "The risk of MTCT of HIV was comparable with these regimens. Infant-only prophylaxis also eliminates the development of NVP resistance in mothers."

Larger studies will be necessary to confirm these promising, but preliminary findings.

03/14/06

Reference
S H Eshleman and others. Development of Nevirapine Resistance in Infants Is Reduced by Use of Infant-Only Single-Dose Nevirapine plus Zidovudine Postexposure Prophylaxis for the Prevention of Mother-to-Child Transmission of HIV-1. The Journal of Infectious Diseases 193(4): 479-481. February 15, 2006.