Background and Importance Bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) has been positioned as a preference drug in the main guidelines in the treatment of HIV. BIC/FTC/TAF has demonstrated an excellent safety and efficacy profile in pivotal studies. In clinical practice few studies have been published concerning these two aspects.

Aim and Objectives To assess the causality of adverse drug reactions (ADRs) of HIV-patients treated with BIC/FTC/TAF.

Material and Methods Observational and retrospective study from May 2019 to March 2021 in a general hospital. The patients were classified into two cohorts based on whether they continued treatment or not after reporting ADRs. The variables analysed were: age, sex, prior and subsequent antiretroviral treatment (if applicable). All ADRs were classified according to the organ class system. The causality was evaluated with The Naranjo Algorithm. This is a method to assess whether there is a causal relationship between an identified untoward clinical event and a drug, using a simple questionnaire to assign probability scores. The total score are: definite (>9), probably (5-8), possible (1-4) and doubtful (0).

Results A total of 1,275 patients were collected, of which 185 patients (14.5%) with at least one ADR were evaluated. The first cohort consisted of 53 patients (4.1%) who changed their treatment (25 men (48%) versus 27 women (52%), median age 56 [IQR 51 – 60]); while the second cohort consisted of 132 patients (10.4%) who maintained such antiretroviral treatment (107 men (80.5%) versus 25 women (18.8%), median age 45 [IQR 33 – 55]). In total 266 ADRs were detected: 216 probable, 46 possible and 4 improbable relationship. A 27.8% were headaches ADRs, 18.8% gastrointestinal effects (diarrhoea, abdominal pain, nausea), 16.2% sleep disorders (insomnia) and 37.2% others.

Conclusion and Relevance The frequency of ADRs of HIV-patients in treatment with BIC/FTC/TAF is low and most of people who suffer it can continue with their treatment. Most ADRs were consider as probably and the most common was the headaches, the gastrointestinal disorders and the insomnia.

Conflict of Interest No conflict of interest