Examination of the Bleeding Risk Involved in the Concomitant Use of Antidepressants and Direct Oral Anticoagulants

Direct oral anticoagulants (DOACs) exert their anticoagulant effects by directly inhibiting thrombin and factor Xa; however, it is important to consider the interactions of DOACs with concomitant medications as some medication may increase the risk of bleeding. Selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenaline reuptake inhibitors (SNRIs) have been reported to reduce platelet aggregation and increase the risk of bleeding. However, there is little evidence regarding the interaction between DOACs and SSRIs or SNRIs in Japanese patients. Therefore, the aim of our study was to investigate the background of bleeding in Japanese patients using SSRIs or SNRIs in combination with DOACs. Seventeen patients who took DOACs in combination with SSRIs or SNRIs between January 2016 and December 2019 at Kyoto University Hospital were included in the study. The observation period was 6 months after commencing DOAC administration and 6 months after of the commencement of SSRI or SNRI administration; moreover, the pre- and post-treatment examinations were performed to assess the changes for each patient. There was no incidence of major bleeding when only DOAC was used, but four of the seventeen patients (23.5％) had major bleeding when antidepressants were administered in addition to DOACs. Known bleeding risk factors such as hypertension, liver dysfunction, smoking history, cancer, peptic ulcer, and thrombocytopenia were not identified as risk factors for major bleeding in this study.