Dagibatran Etexilate: Is There Any Need for Coagulation Monitoring After Initiation?

Activated prothrombin time (aPTT) and thrombin time (TT) can serve as indicators for anticoagulation effect of dabigatran etexilate (Pradaxa), the new oral reversible, competitive inhibitor of thrombin. Further, a significant elevation of these coagulation parameters might demonstrate an increased risk of bleeding probably due to an accumulation of dabigatran.

We present 2 cases of patients with atrial fibrillation as well as mild and moderate renal impairment, which were treated with dabigatran. The patient with the mild renal impairment [creatinine clearance in 24-hour urine collection (CrCl) 50.2 mL/min] had a comorbid slightly disturbed liver synthesis and prolongation of aPTT. Increased risk of bleeding could be identified by significant elevated coagulation parameters (TT and aPTT) during dabigatran treatment. Further speculative in this case increased risk of bleeding might be due to an accumulation of dabigatran possibly caused by comorbid kidney and liver impairment and an effective gain of dabigatran caused by reduced hepatic synthesis of coagulation factors.

Especially in multimorbid elderly patients with comorbid liver and kidney dysfunction, a measurement of coagulation parameters not only before but also soon after initiation of treatment might provide additional information about the risk of bleeding.