Idarucizumab reverses dabigatran anticoagulation. Its mechanism of action is:

• A Competitive antagonism at the thrombin active site
• B Activation of antithrombin III to neutralize circulating dabigatran
• C Monoclonal antibody fragment (Fab) that binds dabigatran with ~350-fold higher affinity than thrombin, sequestering it from circulation ✓
• D Enhanced hepatic glucuronidation and renal clearance of dabigatran

Explanation

Idarucizumab is a humanized monoclonal antibody Fab fragment that binds dabigatran (and its acyl glucuronide metabolites) with ~350-fold higher affinity than dabigatran binds thrombin (Kd ~1 pM vs ~0.3 nM). This creates an essentially irreversible idarucizumab-dabigatran complex that is rapidly eliminated renally, fully reversing dabigatran's anticoagulant effect within minutes. It is specific for dabigatran and does not reverse other DOACs. Andexanet alfa, in contrast, reverses anti-Xa DOACs (rivaroxaban, apixaban) by acting as a decoy FXa.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.