Idarucizumab is a humanized monoclonal antibody fragment (Fab) specifically approved as a reversal agent for the anticoagulant dabigatran. It functions as a specific dabigatran antidote. Idarucizumab binds with extremely high affinity (over 300 times higher than dabigatran's affinity for thrombin) to both the parent drug, dabigatran, and its active metabolites. This binding forms a stable, inactive complex that rapidly neutralizes the anticoagulant effect of free, circulating dabigatran. By restoring thrombin activity, it allows for the urgent reversal of dabigatran's effects in situations of life-threatening bleeding or the need for emergency surgery.