Antiretrovirals

Abstract

Drug resistance leading to virologic failure: 7 case reportsIn a study consisting of 258 patients who underwent routine HIV-1 drug resistance testing from January 2016 to December 2019, seven patients (five males and two females) aged 4-45 years were described, who exhibited drug resistance leading to virologic failure following treatment with raltegravir, emtricitabine/tenofovir disoproxil fumarate, lamivudine/abacavir or lamivudine/ zidovudine for HIV-1 infection [routes, time to reaction onsets and outcomes not stated; not all dosages stated].The patients, who had HIV-1 infection, started receiving raltegravir and emtricitabine/tenofovir disoproxil fumarate [tenofovir disoproxil fumarate/emtricitabine] (n=4); raltegravir and lamivudine/abacavir [abacavir/lamivudine; Kivexa] (n=2); and raltegravir and lamivudine/zidovudine [zidovudine/lamivudine] (n=1). At 24 weeks of therapy, their viral load was noted to be 20-13496 copies/mL. However, at 48 weeks of therapy, their viral load was observed to be 6360-1870000 copies/mL, consistent with virologic failure. Gene mutation analysis revealed presence of several mutations conferring resistance towards nucleoside analogue reverse transcriptase inhibitors and integrase strand transfer inhibitors. The virological failure was considered to be secondary to drug resistance towards treatment with raltegravir and emtricitabine/tenofovir disoproxil fumarate (n=4); raltegravir and lamivudine/abacavir (n=1); lamivudine/abacavir (n=1); and lamivudine/zidovudine (n=1).