Evaluation of adverse events associated with antiretroviral therapy and the relationship to treatment adherence.

Despite the effectiveness of highly active antiretroviral therapy (HAART), many adverse events (AEs) are associated with the use of these drugs, thus affecting treatment adherence. The aim of this study was to evaluate AE incidence with the use of HAART and the relationship to treatment adherence. This was a retrospective observational study conducted with patients who experienced serious AEs related to HAART, resulting in the need to change the therapeutic regimen. To calculate adherence, the dates the patients received HAART were used. From January 2009 to December 2011, 168 AE cases associated with antiretroviral drugs were observed. Of the total study population, 58% of the patients were male. The side effects were associated with 12 drugs, of which 58.3% were nucleoside analogues reverse transcriptase inhibitors (NRTIs). In addition, 16.7% were non-nucleoside reversetranscriptase inhibitors (NNRTIs), and 25% were protease inhibitors (PIs). The NRTIs and PIs presented similar numbers of AEs, whereas the NNRTIs resulted in less than 50% of the reported AEs compared to other drug classes. The low adherence observed in patients with severe AEs that force treatment regimen change suggests that the occurrence of side effects could be one of the obstacles affecting the adherence and thus the effectiveness of HAART.