Nucleoside reverse transcriptase inhibitor-sparing regimen (nonnucleoside reverse transcriptase inhibitor + protease inhibitor) was more likely associated with resistance comparing to nonnucleoside reverse transcriptase inhibitor or protease inhibitor + nucleoside reverse transcriptase inhibitor in the randomized ANRS 121 trial.

The use of nonnucleoside reverse transcriptase inhibitor (NNRTI) + protease inhibitor regimen for the treatment of antiretroviral-naive patients was less successful than classical nucleoside reverse transcriptase inhibitor (NRTI) based regimen and associated with more resistance for protease inhibitors and NNRTIs. The selection for NNRTI resistance was particularly observed in patients with high viral load (>100 000 copies/ml) and low efavirenz trough levels (<1100 ng/ml). Contrary to the results observed in trials evaluating mono or dual protease inhibitors strategies, gag gene mutations were not involved in the low efficacy of this strategy. The NNRTI + protease inhibitor strategy should not be recommended as an antiretroviral first-line regimen, particularly in patients with high viral load at baseline.