Issues of using nevirapine for PMTCT
A major concern with using nevirapine for PMTCT is that NNRTI resistance mutations are commonly observed in both mothers and infants after single-dose nevirapine and may compromise the response to future NNRTI-containing regimens.
Persistence of nevirapine exposure during the postpartum period after administration for PMTCT of HIV
This study aimed to determine nevirapine (NVP) plasma levels during the postpartum period after a single intrapartum nevirapine dose for the prevention of mother-to-child transmission. It was found that significant nevirapine concentrations remained for up to 20 days in the study participants. We could conclude that to ensure coverage is maintained until nevirapine concentrations fall to nonsuppressive levels, 1 month of additional antiretroviral treatment after delivery should be considered to prevent the emergence of resistant viruses.
For further information please refer to Persistence of nevirapine exposure during the postpartum period after intrapartum single-dose nevirapine in addition to zidovudine prophylaxis for the prevention of mother-to-child transmission of HIV-1. [pubmed.gov]
Exposure to nevirapine and subsequent responses to nevirapine based therapy
Whether there were clinically significant consequences in mothers who are subsequently treated with a nevirapine-containing regimen was previously unknown. This study found that women who received intrapartum nevirapine were less likely to have virologic suppression after six months of postpartum treatment with a nevirapine-containing regimen. The study suggests the need for strategies to maximize the benefits of both antiretroviral prophylaxis against mother-to-child transmission of HIV and antiretroviral therapy for mothers. Since this study, PHPT and others have performed research to find ways for women to benefit from single dose nevirapine and avoid the selection of resistance mutations. PHPT-4 and P1032 are examples of such studies.