Dabigatran is an oral thrombin inhibitor approved for the prevention of thromboembolism in patients with atrial fibrillation and for those undergoing orthopedic surgery.
In normal situations, it is not necessary to monitor any laboratory values. However, in the potential overdose situation or in the event of bleeding, it would be useful to assess the anticoagulant status.
The thrombin clotting time (TT) directly assesses the activity of direct thrombin inhibitors (like dabigatran), and displayes a linear dose-response curve over therapeutic concentrations. At high levels, the test frequently exceeds the maximum measurements.
The PT and INR are less sensitive and cannot be recommended.
The activated partial thromboplastin time can provide qualitative assessment of anticoagulant activity but is not sensitive at supratherapeutic doses.
Bottom Line:
In emergency situations, the aPTT and TT are the most effective qualitative methods widely available for determining the presence or absence of anticoagulant effect in patients receiving dabigatran.
References
Rye J, Stangier J, Haertter S, et al. Dabigatranetexilate - a novel, reversible, oral direct thrombin inhibitor: Interpretation of coagulation assays and reversal of anticoagulant activity. Thrombosis and Haemostasis 2010. 103;1116-27.
