Lack of Effect from a Previous Single Dose of Nevirapine on Virologic and Immunologic Responses After 6 Months of Antiretroviral Regimens Containing Either Efavirenz or Lopinavir‐Ritonavir

Abstract

To evaluate the effect of a previous single dose of nevirapine given to prevent mother-to-child transmission of human immunodeficiency virus (HIV) on virologic and immunologic measures after months of an antiretroviral regimen containing either efavirenz or lopinavir-ritonavir. Retrospective subgroup analysis of data from the Phidisa II trial. Six South African research clinics. Patients. A total of 394 women with HIV who completed 6 months of combination antiretroviral regimen containing either efavirenz or lopinavirritonavir as part of the Phidisa II trial. During the screening process for the Phidisa II study, 478 women were asked about previous nevirapine use: 392 women (82%) were nevirapine naïve, and 86 (18%) had received nevirapine. During the study, patients received either an efavirenz-based or lopinavir-ritonavir- based antiretroviral regimen. After 6 months of treatment, virologic (HIV RNA levels) and immunologic (CD4(+) cell count) responses were measured. These data were compared between women with or without previous nevirapine exposure, and between women who received efavirenz versus lopinavirritonavir. After 6 months of treatment, 394 women (324 nevirapine naïve, 70 exposed to nevirapine) had follow-up HIV RNA results. Two hundred twenty-seven (70.1%) of the nevirapine-naïve patients and 48 (68.6%) of the nevirapine-exposed patients achieved HIV RNA levels lower than 400 copies/ml (p=0.89), with CD4(+) cell count increases of 115.5 and 120.4 cells/mm(3), respectively (p=0. 7). Among the nevirapine-exposed women, 27 (75%) of 36 efavirenz-treated and 21 (61.8%) of 34 lopinavir-ritonavir-treated patients had HIV RNA levels lower than 400 copies/ml at months (p=0.31). In this retrospective analysis of a small cohort, previous exposure to a single dose of nevirapine did not affect virologic outcomes after 6 months of either an efavirenz-based or lopinavir-ritonavir-based antiretroviral regimen. As efavirenz is one of the first-line combination antiretroviral therapies administered in Africa, it remains an option for women who received single-dose nevirapine.