Nevirapine Plasma Level After Discontinuation of Short-term Antiretroviral Treatment for the Prevention of Mother-to-child Transmission of HIV and Development of Drug Resistant HIV-1 Variants With 1 or 2 Weeks Continuation of Zidovudine/Lamivudine in Women After Delivery

Three-drug combination of antiretroviral regimens has been used increasingly in HIV-infected pregnant women worldwide, both for the prevention of mother to child transmission of HIV (PMTCT) and for women's own health. Use of these drugs in pregnant women solely for PMTCT means that these drugs will need to be discontinued in the majority of women after delivery.

Certain antiretroviral regimens contain drugs with long half-life (drugs that stay in the body for a longer period of time after discontinuation than other drugs in the same regimen), such as nevirapine (NVP). HIV can easily develop resistance to NVP when NVP is the only drug left in the body (similar to monotherapy). Given two other drugs for up to 1 week after discontinue NVP (to mimic three-drug regimen while waiting for NVP elimination) can help reduce, but not eliminate, the development of resistant virus.

Unfortunately, NVP-containing regimens are the most widely used regimens for pregnant women in developing countries due to its low cost and its availability in fixed-dose combinations. These study will explore how fast NVP is eliminated from women after delivery and to see if given zidovudine/lamivudine (AZT/3TC) for 1 or 2 weeks after NVP discontinuation can help reduce the development of NVP resistant virus.