Incidence and Severity of Drug Interactions before and after Switching Antiretroviral Therapy to Bictegravir/Emtricitabine/Tenofovir Alafenamide in Treatment-Experienced Patients

Background: Switching antiretroviral therapy (ART) in people with HIV (PWH) can influence their risk for drug-drug interactions (DDIs). The purpose of this study was to assess changes in the incidence and severity of DDIs among PWH who switched their ART to bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). Methods: This was a multicenter retrospective cohort study of PWH on ART and at least 1 concomitant medication (CM) who switched to BIC/FTC/TAF between 3/2018 and 6/2019. Using the University of Liverpool's HIV Drug Interaction Database, 2 DDI analyses were performed for each patient. The first assessed patients' preswitch ART regimens with their CM list. The second assessed the same CM list with BIC/FTC/TAF. Each ART-CM combination was given a score of 0 (no or potential weak interaction), 1 (potential interaction), or 2 (contraindicated interaction). A paired t test analyzed changes in total DDI scores following ART switches, and linear regression examined factors contributing to DDI score reductions. Results: Among 411 patients, 236 (57%) had at least 1 DDI present at baseline. On average, baseline DDI scores (SD) were 1.4 (1.8) and decreased by 1 point (95% CI, -1.1 to -0.8) after patients switched to BIC/FTC/TAF (P <. 0001). After adjusting for demographics, baseline ART, and CM categories, switching to BIC/FTC/TAF led to significant DDI score reductions in patients receiving CMs for cardiovascular disease, neurologic/psychiatric disorders, chronic pain, inflammation, gastrointestinal/urologic conditions, and conditions requiring hormonal therapy. Conclusions: Treatment-experienced PWH eligible to switch their ART may experience significant declines in number and severity of DDIs if switched to BIC/FTC/TAF.