The Role of Toxicity-Related Regimen Changes in the Development of Antiretroviral Resistance

Abstract In an effort to evaluate factors associated with the development of antiretroviral (ARV) resistance, we assessed the prevalence of toxicity-related regimen changes and modeled its association to the subsequent development of ARV resistance in a cohort of treatment-naive individuals initiating ARV therapy (ART). A retrospective analysis of patients initiating ART was conducted at the UAB 1917 Clinic from 1 January 2000 to 30 September 2007. Cox proportional hazards models were fit to identify factors associated with the development of resistance to ≥1 ARV drug class. Among 462 eligible participants, 14% (n=64) developed ARV resistance. Individuals with ≥1 toxicity-related regimen change (HR=3.94, 95% CI=1.09–14.21), initiating ART containing ddI or d4T (4.12, 1.19–14.26), and from a minority race (2.91, 1.16–7.28) had increased risk of developing resistance. Achieving virologic suppression within 12 months of ART initiation (0.10, 0.05–0.20) and higher pretreatment CD4 count (0.85 per 50 cells/mm3...