Antifibrinolytic

Tranexamic acid

Also called TXA

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Indications

• Trauma hemorrhage within 3 h of injury (off-label; CRASH-2)
• Postpartum hemorrhage within 3 h of birth (off-label; WOMAN, WHO)
• Cardiac, orthopedic and spine surgery to cut blood loss and transfusion (off-label)
• Mild to moderate TBI within 3 h (off-label; CRASH-3)
• Fibrinolytic bleeding: high LY30 on TEG or ROTEM, or bleeding after thrombolysis (off-label)
• Hemophilia patients having tooth extraction, short term (label)

Dosing

On the quick cards

• Other common pushesPush and Emergency Meds: Analgesia, antiemetics, steroids, diuretics, TXA

Mechanism of action

Tranexamic acid is a synthetic analog of the amino acid lysine. It occupies the lysine-binding sites on the kringle domains of plasminogen, so plasminogen cannot bind the lysine residues of fibrin where tPA activates it, and the plasmin that does form binds fibrin poorly; the clot is spared. At much higher concentrations it also inhibits plasmin directly. It is about 10 times more potent than aminocaproic acid in vitro (label).

Pharmacology

• Hematologic: stabilizes clot (lowers LY30) without raising factor levels or platelets
• Hematologic: CRASH-2 death 14.5% vs 16.0%; benefit was greatest within 1 h, and starting after 3 h raised bleeding deaths
• Hematologic: postpartum bleeding deaths 1.5% vs 1.9%, and 1.2% vs 1.7% when given within 3 h (WOMAN)
• GI: no benefit in GI bleeding and more venous clots (0.8% vs 0.4%; HALT-IT)
• CNS: at high levels it blocks inhibitory glycine and GABA-A receptors, causing seizures (Lecker 2012)
• Cardiovascular: hypotension with rapid IV injection; give no faster than 100 mg/min (label)

Pharmacokinetics

Chemistry

• trans-4-(aminomethyl)cyclohexanecarboxylic acid, C₈H₁₅NO₂, MW 157.2: a synthetic, ring-constrained lysine analog; the trans isomer is the active one
• pKa about 4.3 (carboxyl) and 10.2–10.6 (amine): a zwitterion at pH 7.4, very water-soluble and barely lipid-soluble, so it enters the CNS slowly and leaves by the kidney
• Injection 100 mg/mL (1 g/10 mL) in water, pH 6.5–8.0, preservative-free
• Mixes with electrolyte, dextrose, amino acid and dextran solutions and heparin; not with blood or penicillin solutions (label)

Adverse effects and cautions

In the one-pagers

• Trauma: Primary and Secondary SurveyDamage control resuscitation: TXA within 3 hours for hemorrhagic shock (often SBP <90 or HR >110): 1 g IV over 10 min, then 1 g over 8 h; EMS may give 2 g once
• Obstetric EmergenciesPostpartum hemorrhage: Tranexamic acid: 1 g IV over 10 min; repeat once after 30 min if bleeding: Only within 3 h of birth
• Blood Products and TransfusionMassive transfusion: TXA (CRASH-2): 1 g IV over 10 min, then 1 g over 8 h, within 3 h of injury. Military guidance: one 2 g bolus
• Bleeding, Reversal, HIT and DICReversing anticoagulants in major bleeding: Alteplase, tenecteplase: Cryoprecipitate; tranexamic or aminocaproic acid: Check fibrinogen
• CEN: Uterine Bleeding, Kidney Stones and Deep Neck InfectionsWho goes first: Soaking pads, tachycardia, low BP, faint on standing: Hemorrhage from acute AUB: Access, blood, IV estrogen or tranexamic acid, gynecology now
• After Cardiac SurgeryFirst hours and bleeding: Fibrinolysis: Tranexamic acid

In the algorithms

• Traumatic Cardiac Arrest
• Field Delivery and Newborn Care
• Massive Hemoptysis
• Massive Pulmonary Embolism
• Massive Hemorrhage
• Postpartum Hemorrhage

Sources

1. FDA label: Cyklokapron (2025)
2. CRASH-2 (Lancet 2010)
3. WOMAN (Lancet 2017)
4. Lecker 2012 (JCI, seizures)

For education and exam preparation only. Follow your institution’s protocols. Typical adult values for study. Follow the order, the label and your institution's protocols.