HIV-1 genotype after interruption of non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy and virological response after resumption of the same regimen.

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) have a longer half-life than nucleoside reverse transcriptase inhibitor (NRTIs). Simultaneous interruption of all drugs exposes the patients to NNRTI monotherapy. This study evaluated HIV-1 genotype after treatment interruption (TI) of NNRTI-based antiretroviral therapy (ART) and virological response after resumption of the same ART regimen. A prospective study was conducted in HIV-1-infected patients who enrolled into a CD4-guided TI study. All patients continued dual NRTIs for a further 7-10 days at NNRTI TI. HIV-1 genotypic assay was performed prior to resumption of the same ART regimen. Forty-three patients required ART resumption after TI from NNRTI-based regimens. Mean age was 42.7 years; 44% were men. Median CD4 and HIV-1 RNA at the time of ART resumption were 178 cell/mm(3) and 5.78 log copies/mL, respectively. HIV-1 genotype revealed no mutations contributed to NRTI or NNRTI resistance. Of all, 56% and 100% patients achieved undetectable HIV-1 RNA at three and six months, respectively. Median CD4 were 386 and 419 cells/mm(3) at the corresponding periods. In conclusion, continuation of dual NRTIs for 7-10 days after TI of NNRTI-based regimens can minimize the risk of acquired NNRTI resistance. With this strategy, the same regimen can be used for resumption and also yield good virological and immunological outcomes.