Critical
Dabigatran × Rivaroxaban
Direct thrombin inhibitor×Direct oral anticoagulants (factor Xa inhibitors)
Mechanism
Rivaroxaban blocks factor Xa; dabigatran blocks thrombin. Different targets but additive anticoagulation with no therapeutic benefit.
Symptoms
Gum bleeding, epistaxis, bruising without trauma, blood in urine or stool, menorrhagia. Severe cases include gastrointestinal or intracranial haemorrhage, gross haematuria with renal colic, spontaneous retroperitoneal haematomas. Symptoms may appear within days of co-prescription.
Management
The combination is not prescribed. When switching DOACs, stop the first and start the second at the next scheduled dose without overlap. For high thrombotic risk with renal impairment, bridge with a parenteral anticoagulant (low molecular weight heparin).