Stavudine in zidovudine (ZDV)-experienced compared with ZDV-naive patients.

Objective: To assess the effect of prior zidovudine (ZDV) use on subsequent response to stavudine (D4T)-containing regimens.
Design: Analysis of data from prospective observational database.
Methods: Patients were ZDV-experienced if they had previously received more than 90 days of ZDV and ZDV-naive if they had never received ZDV. HIV-1 RNA and CD4 cell counts were compared at 3, 6, and 12 months after initiation of D4T. Univariate and multivariate analyses were performed, adjusting for baseline HIV-1 RNA and CD4 cell count, age, sex, race, HIV transmission category, time since enrollment, and protease inhibitor use.
Results: No difference was found between ZDV-experienced (n = 130) and naive (n = 98) patients in age, sex, race, transmission category, use of a concurrent protease inhibitor, or baseline CD4 cell count and HIV-1 RNA. There was no difference in the median decline in HIV-1 RNA (-1.29 log10 copies/ml for experienced patients versus -1.19 log10 copies/ml for naive patients; P = 0.39), in achieving HIV-1 RNA < 400 copies/ml at 3 months (51% versus 49%; P = 0.79) or 6 months (48% versus 56%; P = 0.33). There was no difference in CD4 cell response (+73 x 10(6)/l versus + 87 x 10(6)/l; P = 0.51). By multivariate adjustment in a repeated measures analysis, there was no significant difference in achieving undetectable HIV-1 RNA or in CD4 cell response between experienced and naive patients.
Conclusion: No difference in response to a D4T-containing regimen between ZDV-experienced and naive patients was found over a 1-year period. In contrast to previous trials, most patients in this study also received a protease inhibitor. These findings may be more relevant in the current era of highly active antiretroviral therapy.