Background: Either LPV/r or EFZ plus a two nucleoside reverse-transcriptase inhibitors (NRTIs) are recommended by the current guidelines all around the world as the main background drugs for initial therapy of human immunodeficiency virus type 1 (HIV-1) infection. This indication is based in results of clinical trials, but patients who participate in these studies usually are greatly motivated to continue their prescribed regimen, and can be different from the "real life". Therefore, clinical practice often cannot reproduce published results.