Introduction: Nevirapine (NVP) resistance may decrease the effectiveness of viral suppression with NVP-based antiretroviral therapy (ART) in women infected with human immunodeficiency virus (HIV) with previous exposure to single-dose NVP. However, the alternative lopinavir-ritonavir-based ART regimen is more expensive. Our objectives were to project the tradeoffs regarding life expectancy, cost, and cost-effectiveness of these ART regimens for NVP-exposed, HIV-infected women in South Africa.
Methods: We developed a simulation model in which NVP-exposed, HIV-infected South African women received 1 of 5 treatment strategies: HIV care without ART, NVP-based ART, lopinavir-ritonavir-based ART, NVP-based ART followed by lopinavir-ritonavir-based ART, or lopinavir-ritonavir-based ART followed by NVP-based ART. The prevalence of NVP resistance was 39%; other data were obtained from the published literature.
Results: Projected life expectancy was 43.7 months for women who did not receive ART, 77.4 months for women who received a single NVP-based regimen, and 84.5 months for women who received a single lopinavir-ritonavir-based regimen. NVP resistance reduced survival time by up to 11.6 months among women who received NVP-based ART. The cost-effectiveness of NVP-based ART was $800 (US dollars) per year of life saved, compared with no ART, and the cost-effectiveness of lopinavir-ritonavir-based therapy was $4400 per year of life saved, compared with NVP-based ART. Lopinavir-ritonavir followed by NVP-based ART yielded the greatest life expectancy (105.4 months), had a cost-effectiveness of $2300 per year of life saved, and, if the efficacy of NVP-based regimens improved >6 months postpartum, further increased survival.
Conclusions: NVP resistance substantially decreased the projected survival time associated with NVP-based ART, and lopinavir-ritonavir-based ART resulted in a superior survival time but at higher cost. A sequential regimen starting with lopinavir-ritonavir-based ART followed by NVP-based ART maximized projected survival and was cost effective in South Africa.