Tranexamic acid (TXA) is administered for a patient with major haemorrhage. Its mechanism of action is:

• A Direct thrombin inhibitor
• B Activates thrombomodulin, enhancing protein C-mediated anticoagulation
• C Inhibits von Willebrand factor cleavage by ADAMTS-13
• D Synthetic lysine analogue that blocks plasminogen binding to fibrin, inhibiting fibrinolysis ✓

Explanation

Tranexamic acid is a synthetic lysine analogue that competitively inhibits the lysine-binding sites on plasminogen (and plasmin), preventing its attachment to fibrin. This blocks plasmin-mediated fibrinolysis, stabilising formed clots. The CRASH-2 trial established that early TXA (within 3 hours of injury) significantly reduces mortality from bleeding in trauma. It should be given as 1 g IV over 10 minutes followed by 1 g IV over 8 hours; delayed administration (>3 hours) may paradoxically increase mortality.

Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.