Background Antiretroviral treatment with a three drug-regimen is the initial treatment recommended for chronic HIV infection. For various reasons, the combination of three drugs can be modified to a two-drug regimen.

Purpose To analyse the change from a three-drug antiretroviral treatment regimen (HAART) to a two-drug regimen in HIV+ patients: reason for change and effectiveness.

Materials and Methods Cross-sectional retrospective study of HIV-infected patients in treatment with two active antiretroviral drugs from January 2010 to April 2012. The data was obtained from the medical history and the Farmatools application for external patients. Effectiveness was evaluated by the viral plasma load (VPL) and the CD4 cell count, measured at 24 weeks. Viral load suppression (VLS) was defined as less than 50 copies/ml.

Results A total of 30 patients were studied, with the following two-drug regimens: 5 patients with boosted Atazanavir (ATZr)/Maraviroc (MRV); 4 patients with boosted Darunavir (DRVr)/Etravirina (ETV); 13 patients with DRVr/MRV; 6 patients with DRVr/Raltegravir (RAL); 1 patient RAL/MRV and 1 patient with boosted Fosamprenavir (FPVr)/RAL. The reasons for the change to a two-drug regimen were the following: 12 changes were determined by drug resistance tests, 6 due to side effects of previous HAART treatment and 12 to simplify their antiretroviral treatment. The answers obtained are shown in table 1. Patients who did not reach viral load suppression at 24 weeks were taking a regimen composed of ATZr/MRV (2 patients) and DRVr/MRV (1 patient).

Conclusions The main reasons for changing from HAART to two-drug regimens were drug resistance tests and simplification of the antiretroviral treatment. Taking into account the limitation of the study due to its short follow-up and the limited number of patients, we can say that in our study, the change to a treatment with two active antiretroviral drugs seems to be at least as effective as the three-drug HAART regimen.

No conflict of interest.