American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the recommended reversal agent for dabigatran overdose?

1. Warfarin

2. Andexanet alfa

3. Idarucizumab

4. Vitamin K

The correct answer is: Idarucizumab

The recommended reversal agent for dabigatran overdose is idarucizumab. Idarucizumab is a specific monoclonal antibody fragment that binds to dabigatran and its active metabolites, effectively neutralizing their anticoagulant effects. It works rapidly, providing IVD (in vitro) evidence of complete reversal of dabigatran's anticoagulation within minutes of administration, which is crucial in emergency settings. This characteristic makes idarucizumab the preferred treatment when addressing serious bleeding or urgent surgical needs in patients who have taken dabigatran, as it allows for immediate restoration of normal coagulation. Other agents, such as andexanet alfa, are specific to the reversal of factor Xa inhibitors, which makes them unsuitable when dealing with a direct thrombin inhibitor like dabigatran. Similarly, warfarin and vitamin K are anticoagulants and their reversal agents used for vitamin K antagonists, not applicable here.