NRTI and NNRTI resistance mutations were documented in more than 90% of patients who experienced treatment failure on an initial regimen of d4T/3TC/nevirapine.
The generic fixed-dose combination of d4T/3TC/nevirapine is widely used in resource-poor settings because of its simplicity and affordability. Although initial experience with this combination was positive in terms of tolerability and clinical efficacy, virologic failure has become increasingly common. What are the genotypic consequences of such failure, and what are the implications for second-line regimens in resource-poor settings?
Investigators in Thailand conducted genotypic resistance testing among 98 patients who achieved undetectable viral loads but then subsequently experienced virologic failure (>1000 copies/mL on two consecutive measurements) with an initial regimen of d4T/3TC/nevirapine. At the time of treatment failure, patients…