Potential Drug-Drug Interactions and Related Factors among Geriatric Outpatients of a Tertiary Care Hospital

(1) Background: Drug-drug interactions (DDIs) possess the potential to lead to a range of clinically significant consequences in the older population. (2) Aims: To investigate the prevalence and associated factors of DDIs among older patients within an outpatient setting of a university hospital. (3) Methods: This is a descriptive analysis of patients aged ≥65 years, who received a minimum of two medications. The electronic medical records were obtained from the outpatient clinic of a tertiary care hospital between November 2021 and November 2022. The outcomes were analyzed using descriptive and regression analysis. (4) Results: The study enrolled 10,877 patients, with a mean age of 74.3 ± 6.8 years. The prevalence of major DDI was 36.8%. Factors associated with major DDI were age (odds ratio [OR] 1.03), female sex (OR 1.23), polypharmacy (OR 2.27-13.78), metabolic disease (OR 1.89), psychiatric disorder (OR 1.79), cardiovascular disease (OR 1.51), musculoskeletal disease (OR 1.37), central nervous system disease (OR 1.24), and tuberculosis (OR 0.18). There was a significant difference observed in the primary healthcare facilities for emergency medicine (OR 1.72), orthopedics (OR 1.36), internal medicine (OR 1.29), and radiology (OR 0.45). (5) Conclusions: Major DDI was prevalent among older patients receiving care at outpatient settings. Several factors linked to major DDIs were identified. Developing appropriate strategies to improve the prescription process and avoid any missed interactions with geriatric patients is recommended.