Moderate
Established
Description
Low-dose aspirin combined with dabigatran increases bleeding risk; clinical evidence suggests a 2-fold increase in major bleeding events.
Mechanism
Aspirin irreversibly inhibits platelet COX-1, reducing thromboxane A2 and impairing primary hemostasis; dabigatran inhibits secondary hemostasis by blocking thrombin.
Clinical Significance
The RE-LY trial showed substantially higher bleeding rates when aspirin was combined with dabigatran versus dabigatran alone.
Management
Use combination only when there is a clear indication; monitor closely; add PPI; use lowest effective aspirin dose.