Background: Prevalence of potential drug-drug interactions (PDDIs) between antiretroviral drugs (ARVs) and co-medications was high in 2008 in a Swiss HIV Cohort Study (SHCS) survey. We reassessed the prevalence of PDDIs in the era of human immunodeficiency virus (HIV) integrase inhibitors (INIs), characterized by more favorable interaction profiles.

Methods: The prevalence of PDDIs in treated HIV-positive individuals was assessed for the period 01-12/2018 by linkage of the Liverpool HIV drug interactions and SHCS databases. PDDIs were categorized as harmful (red flagged), of potential clinical relevance (amber flagged), or of weak clinical significance (yellow flagged).

Results: In 9298 included individuals, median age was 51 years (IQR, 43-58), and 72% were males. Individuals received unboosted INIs (40%), boosted ARVs (30%), and nonnucleoside reverse transcriptase inhibitor (NNRTIs) (32%)-based regimens. In the entire cohort, 68% received ≥1 co-medication, 14% had polypharmacy (≥5 co-medications) and 29% had ≥1 PDDI. Among individuals with co-medication, the prevalence of combined amber and yellow PDDIs was 43% (33% amber-mostly with cardiovascular drugs-and 20% yellow-flagged PDDIs) compared to 59% in 2008. Two percent had red-flagged PDDIs (mostly with corticosteroids), the same as in the 2008 survey. Compared with 2008, fewer individuals received boosted ARVs (-24%) and NNRTIs (-13%) but the use of co-medications was higher.

Conclusions: Prevalence of PDDIs was lower with more widespread use of INIs in 2018 than in 2008. Continued use of boosted regimens and increasing needs for co-medications in this aging population impeded lower rates of PDDIs.