Durability of the first antiretroviral treatment regimen and reasons for change in patients with HIV infection.

BACKGROUND: To study the durability of the drugs and coformulations currently used in the first treatment regimen of antiretroviral therapy (ART) for HIV patients, and to examine the reasons for changing this medication. METHODS: A retrospective observational multicenter study of patients with HIV infection who started a first-line ART regimen between January 2007 and June 2010. The primary outcome variable was the durability of this first ART regimen until discontinued or amended and the reasons for the change. Survival analysis of durability was performed using Kaplan-Meyer curves analysis, and a Cox multiple regression model was constructed to identify associated factors. RESULTS: A first-line ART regimen was initiated for 600 patients; after 1 year, it had been changed in 172 (28%) cases, with a median duration of 31 months. The main reason for change was toxicity (20.5% of all patients), followed by loss to follow-up (8.3%) and virological failure (5.3%). The most common type of toxicity was gastrointestinal (30%), followed by cutaneous (23%) and neuropsychiatric (18%). The use of non-nucleoside reverse transcriptase inhibitors (NNRTIs) was associated with greater durability than that of protease inhibitors (43 months vs 21 months; P = .001). CONCLUSIONS: The durability of the first-line ART regimen, based on current antiretroviral drugs and coformulations, is about 2.5 years, with toxicity being the main reason for its modification. Gastrointestinal toxicity is the type most commonly reported. NNRTI treatment is associated with greater durability of the first treatment regimen.