Effect of Prior Nucleoside Use on the Two-Year Virological Response to an Initial Protease Inhibitor Regimen in HIV-Infected Patients

Abstract

Purpose: This retrospective study investigates the effect of prior nucleoside (nucleoside reverse transcriptase inhibitor [NRTI]) experience on 2-year virologic response to an initial protease inhibitor-highly active antiretroviral therapy (PI-HAART) regimen. Method: 152 patients who started a PI (excluding saquinavir hard gel capsule [hgc] as a sole PI) with two NRTIs between January 1996 and May 1998 at two HIV treatment sites were included. Results: 109 patients (71%) were NRTI experienced. 106 patients received two new NRTIs, and 32 received one new NRTI. Overall, 51% of patients had a virologic response (HIV viral load <400 copies/mL); the mean follow-up was 28 months. Virologic response was associated with the use of at least one new NRTI (relative risk [RR] 2.1; p = .031) but not with prior NRTI experience (p = .19). A complete virologic response was most likely to occur when two new NRTIs were used (RR 2.3) rather than one new NRTI (RR 1.8), but this was not significant (p = .12). Conclusion: This study suggests that prior nucleoside experience is not a key predictor of 2-year virologic response in patients who receive at least one new NRTI in an initial PI-HAART regimen.

Keywords:

• nucleoside reverse transcriptase inhibitor
• virologic response
• protease inhibitor