Prevalence of Polypharmacy and Potential Drug-Drug Interactions Associated with Risk Factors in the Era of HIV Integrase Inhibitors: A Prospective Clinical Study.

People living with human immunodeficiency virus (PLWH), with the availability of modern antiretroviral drugs, have multiple comorbidities, which increase the risk of polypharmacy and potential drug-drug interactions (PDDIs). This is a particularly important issue for the aging population of PLWH. This study aims to review the prevalence and risk factors for PDDIs and polypharmacy in the era of HIV integrase inhibitors. A cross-sectional, two-center, prospective observational study was conducted on Turkish outpatients between October 2021 and April 2022. Polypharmacy was defined as the use of ≥5 non-HIV medications, excluding over-the-counter (OTC) drugs, and PDDIs were classified using the University of Liverpool HIV Drug Interaction Database (harmful/red flagged and potentially clinically relevant/amber flagged). The median age of the 502 PLWH included in the study was 42 ± 12.4 years and 86.1% were males. Most individuals (96.4%) were given integrase-based regimens (unboosted 68.7% and boosted 27.7%). In total, 30.7% of individuals were taking at least one OTC drug. The prevalence of polypharmacy was 6.8% (9.2% when OTC drugs were included). During the study period, the prevalence of PDDIs was 1.2% for red flag PDDIs and 16% for amber flag PDDIs. CD4⁺ T cell count >500 cells/mm³, number of comorbidities ≥3, comedication with drugs affecting blood and blood-forming organs, cardiovascular drugs, and vitamin/mineral supplements were associated with red flag or amber flag PDDIs. Drug interaction prevention is still important in HIV care. Individuals with multiple comorbidities should be closely monitored for non-HIV medications to prevent PDDIs.