Tranexamic acid (TXA)
Formal Definition
Tranexamic acid (TXA) — an antifibrinolytic lysine analog that reversibly binds to plasminogen and plasmin, blocking the lysine-binding sites needed for fibrin binding, thereby preventing plasmin-mediated fibrin degradation and stabilizing existing clots; used as a 1g IV bolus followed by 1g infusion over 8 hours for acute traumatic hemorrhage (within 3 hours of injury per CRASH-2 trial), topically or IV for surgical bleeding reduction, orally for heavy menstrual bleeding, and in select cases for postpartum hemorrhage (WOMAN trial). Contraindicated or used with caution in patients with active thromboembolic disease (DVT, PE, stroke, active MI) due to theoretical clot-stabilization concerns.
How It's Used on the Ward
"TXA" or "tranexamic" — the antifibrinolytic that slows bleeding by stabilizing clots; given for major trauma, postpartum hemorrhage, orthopedic surgery (especially joint replacement with high blood loss), heavy menstrual bleeding, and epistaxis; one-gram bolus then drip, or repeat PO doses; timing matters — give within 3 hours for trauma to get benefit.
Example
""24-year-old motorcycle crash victim, multiple long-bone fractures, BP 86/58, HR 128, lactate 6.4, ongoing bleeding from open femur fracture and pelvic ring disruption, massive transfusion protocol activated. Trauma team: 'Add TXA 1 gram IV bolus now, then 1 gram infusion over 8 hours — he is 45 minutes from injury, well within the 3-hour window.' TXA given at scene-to-hospital arrival 1:18 mark. Patient de-escalates bleeding; further resuscitation continues; survives to OR.""
Clinical Context
Mechanism: blocks fibrinolysis by inhibiting plasminogen activation and plasmin binding to fibrin. Key trials: CRASH-2 (2010) showed mortality benefit in trauma patients receiving TXA within 3 hours of injury; CRASH-3 (2019) showed no significant mortality benefit in isolated TBI but reduction in head-injury-related death in mild-to-moderate TBI; WOMAN trial (2017) showed death from bleeding reduction in postpartum hemorrhage. Indications: (1) Trauma — within 3 hours of injury. (2) Postpartum hemorrhage. (3) Surgical bleeding — orthopedic (joint replacement, spine), cardiac, liver resection, major abdominal surgery. (4) Heavy menstrual bleeding — oral formulation. (5) Epistaxis — topical. (6) Dental bleeding in hemophilia. Contraindications: active venous or arterial thromboembolic disease, subarachnoid hemorrhage (concerns about cerebral ischemia), hypersensitivity. Dose: 1g IV over 10 minutes, then 1g over 8 hours (for trauma); surgical dosing varies; oral 1-1.5g TID for HMB. Counseling: timing matters — benefit drops substantially or reverses after 3 hours. Side effects: generally well-tolerated; mild GI upset, rare thromboembolic events when overused. CRASH-2 efficacy in low-resource trauma settings is well-established; cost is very low.