Spontaneous splenic hemorrhage after initiation of dabigatran (Pradaxa) for atrial fibrillation.

Dabigatran etexilate (Pradaxa; Boehringer Ingelheim Pharmaceuticals, Inc, Ridgefield, CT) is an oral anticoagulant that produces a reliable, dose-dependent anticoagulant effect without the need for routine laboratory monitoring. Dabigatran is a direct thrombin inhibitor, acting like other members in its class (bivalirudin, argatroban) to impede the clotting process through selective and reversible binding with both free and clot-bound thrombin. Dabigatran anticoagulates rapidly: plasma levels peak 2 hours after absorption, with a half-life that ranges between 12 and 17 hours. Dabigatran was approved by the Food and Drug Administration in October 2010 after it compared favorably with warfarin in a large clinical trial studying its efficacy in stroke prevention in atrial fibrillation. Currently, there is no laboratory test on the market by which a physician can quantify the anticoagulation effect of dabigatran, nor is there any antidote to reverse a life-threatening bleed should it occur. We present a case of a patient with splenic hemorrhagic soon after initiation of dabigatran.