Treatment limitations imposed by antiretroviral therapy: a comparison of first line regimens containing boosted-protease inhibitors and non-nucleoside reverse transcriptase inhibitors

NNRTI-based ART is mainly used as first-line treatment for HIV in resource-limited settings. Anecdotal evidence suggests a greater chance of resistance from failing NNRTI-based regimens compared to boosted-PI. Development of resistance mutations among individuals who initiated ART with boosted-PIs were compared with those who initiated ART with NNRTIs in a retrospective study of ART-naïve individuals in BC, Canada. A total of 1666 participants initiated ART with 818 (49.1%) on NNRTI-based regimen. Participants who initiated NNRTI-based regimens had more resistance mutation compared to those on boosted-PI (40.3% vs. 27.3%, p <0.001). After switching therapy to second line, the odds of achieving two consecutive pVLs of <50 copies/ml after switching was inversely associated with NNRTI use in the initial ART regimen (OR: 0.32; 95% CI: 0.11 - 0.97). The use of NNRTI-based first-line regimens was associated with more ART drug resistance patterns which limit the number of available second-line drug choices.