<![CDATA[Drug interactions are an important medication safety concern among elderly patients with ischaemic heart disease (IHD), particularly because age-related physiological changes and comorbidities may increase vulnerability to adverse drug effects. This study aimed to identify potential drug interactions and describe the sociodemographic and clinical characteristics of elderly patients with IHD. A quantitative, descriptive study with a retrospective cross-sectional design was conducted using medical records of elderly patients treated between January and December 2025. The study included 100 patients aged 60 years or older who had an IHD diagnosis and documented concurrent use of more than one medication. Data were collected through medical record observations and analyzed using descriptive statistics, including frequency distributions and percentages. Potential drug interactions were screened using the Medscape Drug Interaction Checker and classified according to their mechanisms and severity. The results showed that 58% of patients were male, while 83% were aged 60–74 years. Bisoprolol was the most frequently prescribed medication, accounting for 92% of patients. Furthermore, 96% of patients had comorbidities, and 62% received fewer than five medications. Potential drug interactions were identified in 90% of patients, with a total of 185 interaction events. Pharmacodynamic interactions predominated, accounting for 94.6% of all identified interactions, while pharmacokinetic interactions represented 5.4%. Regarding severity, moderate interactions were the most common (82.7%), followed by major interactions (16.2%) and minor interactions (1.1%). The aspirin–bisoprolol combination was the most frequently identified interacting drug pair, accounting for 31.4% of interaction events. These findings demonstrate the high prevalence of potential drug interactions among elderly patients with IHD, even when most patients receive fewer than five medications. Routine medication review, systematic interaction screening, and continuous clinical monitoring are therefore essential. Pharmacists should collaborate with physicians and other healthcare professionals to assess interaction significance, optimize pharmacotherapy, and improve medication safety.]]>
