Objective: The aim of this study was to investigate the risk of hemorrhage in concomitant therapy with direct oral anticoagulants (DOACs) and class IV antiarrhythmic drugs.
Materials and methods: First, disproportionality analysis (DPA) was performed using the Japanese Adverse Drug Event Report (JADER) database to investigate the risk of hemorrhage with DOACs. Second, a cohort study was performed using electronic medical record data to confirm the results of the JADER analysis.
Results: In the JADER analysis, hemorrhage was significantly associated with treatment with edoxaban and verapamil (reporting odds ratio = 1.66; 95% confidence interval (CI) = 1.04 - 2.67). The cohort study revealed that hemorrhage incidence significantly differed between the verapamil-treated group and the bepridil-treated group, with a higher risk for hemorrhage in the verapamil group (log-rank test: p < 0.001). The multivariate Cox proportional hazards model also showed that the verapamil and DOAC combination was significantly associated with hemorrhage events compared with the bepridil and DOAC combination (hazard ratio (HR): 2.87, 95% CI: 1.17 - 7.07, p = 0.022). Furthermore, creatinine clearance (Ccr) ≥ 50 mL/min was significantly associated with hemorrhage events (HR: 2.72, 95% CI: 1.03 - 7.18, p = 0.043), and verapamil was significantly associated with hemorrhage in patients with Ccr ≥ 50 mL/min (HR: 3.58, 95% CI: 1.36 - 9.39, p = 0.010) but not in patients with Ccr < 50 mL/min.
Conclusion: Verapamil increases the risk of hemorrhage in patients on DOACs. Dose adjustment of DOACs based on renal function may prevent hemorrhage when verapamil is concomitantly administered.