Background: A fixed-dose combination of stavudine, lamivudine, and nevirapine (GPO-VIR) is the most affordable antiretroviral therapy (ART) regimen in Thailand. The data of nevirapine (NVP) level and efficacy of this fixed-dose combination is limited.

Material and Method: Patients who were initiated GPO-VIR in 2004 were enrolled. NVP levels at 12 weeks were determined. Patients were followed for 24 weeks.

Results: Fifty-nine patients with a mean age of 36.4 years and 54% male were enrolled. Mean body weight was 54.7 kgs. Median baseline CD4 and HIV-RNA were 29 cells/mm³ and 270,000 (5.4 log₁₀) copies/mL, respectively. Mean plasma NVP levels at 12 weeks was 6.4 mg/L. By linear regression, female gender (p = 0.042), and higher weight (p = 0.020) were associated with lower NVP levels. At 24 weeks, 78% achieved undetectable HIV-RNA and median CD4 was 156 cells/mm³.

Conclusion: NVP levels and 24-week efficacy of GPO-VIR are favorable. According to the affordable cost, GPO-VIR should be an appropriate initial regimen for Thai HIV-infected patients in resource-limited settings.

Keywords: HIV, Nevirapine level, Nevirapine, GPO-VIR, Efficacy