Interactions among antithrombotic agents in acute coronary syndrome: association with bleeding and hospital length of stay

Acute coronary syndrome management requires antiplatelets and anticoagulants to prevent thrombus formation. However, concurrent use may lead to drug interactions and harmful effects – such as bleeding – that can impact the patient’s treatment process, including the length of stay (LOS). This study aimed to analyze potential and actual drug interactions among antithrombotic agents and their association with LOS. This retrospective study was conducted using electronic medical records and laboratory results from patients during the period October 2024–March 2025. The inclusion criteria were hospitalized patients receiving antithrombotic agents. A total of 176 patients were included using a consecutive sampling method. Drug interactions were analyzed using Micromedex. Bleeding was evaluated using hemoglobin levels and clinical signs based on BARC criteria. Bleeding was observed in 14 patients, of whom 57.14% received three or more antithrombotic agents. The most common potential pharmacodynamic interaction occurred between aspirin and clopidogrel. The median LOS was 4 days (IQR 4), and the median number of potential pharmacodynamic interactions was 3 (IQR 3). The number of drugs and LOS were significantly higher in the bleeding group (p < 0.05). The number of drugs and the type of ACS were significant factors influencing LOS.