LAUSR

To evaluate the reasons for changing to monotherapy with protease inhibitors, together with the proportion and reasons for the interruption to treatment, in patients who have been treated at some point with cobicistat-boosted darunavir (DRV/c). Outpatients in a tertiary hospital. Observational retrospective study to evaluate monotherapy with DRV/c (800 mg/150 mg) in adult patients with human immunodeficiency virus infection, from December 2014 to July 2022. Demographic variables, viral load, cluster of differentiation 4 lymphocyte lymphocyte count, and antiretroviral therapy were assessed. 42 patients were included. 36% of the patients were undergoing monotherapy at the time of the analysis. The main reason for discontinuation was poor adherence. At time of analysis, 80% of the patients in monotherapy had an undetectable viral load. Antiretroviral therapy recommendations advise against exposing the patient to functional monotherapy with a single drug due to the high risk of virological failure and the onset of resistance to a single drug. Following the analysis of the results, DRV/c in monotherapy is not an effective strategy in the medium and long term due to factors such as lack of adherence or virological failure, although it can be maintained in specific circumstances. Therefore, patients undergoing monotherapy require close monitoring.