[First antiretroviral therapy regimen in HIV-infected patients. Durability and factors associated with therapy...

To analyze the durability of the first highly active antiretroviral therapy (HAART) regimen used in naïve HIV-infected patients and the factors leading to therapy changes.

Multicenter, retrospective study of naïve HIV-infected patients from 5 hospitals in Málaga (southeast Spain), who started HAART between January 1997 and December 2003. The main outcome measure was median time to the first change in the antiretroviral regimen. A descriptive analysis was performed and Kaplan-Meier curves were used to assess durability of the first HAART used. Independent factors associated with durability were evaluated with a Cox multiple regression model.

A total of 603 patients started HAART, and 130 (21.6%) remained under the same treatment at the latest evaluation point. Median time on the same HAART was 17.5 months, and reached 24 months when cases of simplification or structured intermittent treatment interruption were excluded from the analysis. HAART had been interrupted in 36% by one-year of follow-up. Toxicity was the main cause of switching therapy (25%), followed by simplification (19%), and virologic failure (15%). Longer durability of HAART was observed in non-nucleoside reverse transcriptase inhibitor (NNRTI) regimens, (P < 0.046; HR, 1.58) and in those with less than 5 pills (P < 0.001; HR, 2.05).

Median durability of the first HAART was almost one year and a half, and discontinuation was mainly due to toxicity. NNRTI regimens showed longer durability, which could be attributable to a lower pill burden, at least in part.