Potential drug–drug interactions among hospitalised cardiac patients in Nepal: a prospective observational study

Abstract

Background Drug–drug interactions (DDIs) are a significant concern for patients on complex therapeutic regimens, especially involving cardiovascular medications, which are frequently implicated in these interactions.Objectives This study used a standardised interaction database to determine the frequency, severity and risk factors associated with potential DDIs (pDDIs) among cardiovascular disease (CVD) in-patients.Methods The prospective cross-sectional study was conducted at a tertiary care hospital in Nepal from April 2024 to October 2024. A total of 106 eligible CVD in-patients were evaluated for pDDIs using the Lexicomp DDI checker database, and the interactions were categorised based on severity and risk rating. Binary logistic regression identified factors associated with pDDIs.Results The study identified 621 pDDIs using the Lexicomp database, with median values of 8 pDDIs per patient. Patients with at least one pDDI comprised 64.2% of the sample. Most pDDIs were of moderate severity (77.3%) with risk ratings of C (65.7%). The most common cardiovascular medications involved in the detected DDI pairs were diuretics (31.2%), antiplatelets and anticoagulants (23.8%) and calcium channel blockers (12.2%). Multivariate binary logistic regression revealed that patients who stayed longer (adjusted OR (AOR) 9.08, 95% CI 1.027 to 80.216, p=0.047), those receiving more medications (AOR 18.85, 95% CI 2.975 to 119.370, p=0.002) and those who were admitted to the intensive cardiac care unit (AOR 16.31, 95% CI 2.728 to 97.461, p=0.002) were significantly more likely to experience pDDIs.Conclusions This study found a higher prevalence of pDDIs. It is advisable to incorporate medication reviews into routine cardiac care and use a drug interaction checker to identify pDDIs.