Major
Dabigatran × Rifampicin
Direct thrombin inhibitor×Antituberculous antibiotic
Mechanism
Rifampicin strongly induces P-glycoprotein, the main dabigatran clearance route. Dabigatran plasma levels fall by 66%; stroke prevention in atrial fibrillation or VTE treatment fails.
Symptoms
The patient feels nothing. Stroke risk in atrial fibrillation rises, as do deep vein thrombosis and pulmonary embolism risks.
Management
The combination is not prescribed. Alternative anticoagulants: warfarin with INR monitoring or low molecular weight heparin for short courses. Induction persists for 2 weeks after rifampicin stops.