What are the recommended dosing regimens, indications, and contraindications for anti‑fibrinolytic agents such as tranexamic acid and epsilon‑aminocaproic acid?

Anti-Fibrinolytic Drugs: Dosing, Indications, and Contraindications

Tranexamic Acid (TXA)

Trauma and Major Bleeding

Administer tranexamic acid 1 g IV over 10 minutes as early as possible (ideally within 1 hour, but no later than 3 hours after injury), followed by 1 g IV infusion over 8 hours for bleeding trauma patients. 1

• Critical timing window: Treatment within ≤1 hour reduces death from bleeding by 32% (RR 0.68), treatment between 1-3 hours reduces death by 21% (RR 0.79), but treatment after 3 hours may increase mortality (RR 1.44) 1
• The CRASH-2 trial (n=20,211) demonstrated significant mortality reduction: all-cause mortality 14.5% vs 16.0% (RR 0.91), death from bleeding 4.9% vs 5.7% (RR 0.85) 1
• Pre-hospital administration should be considered to ensure early treatment, particularly for patients en route to hospital 1
• Do not await viscoelastic testing results before administering TXA in bleeding trauma patients 1

Post-Partum Hemorrhage

Administer tranexamic acid 1 g IV over 10 minutes within 3 hours of birth for clinically diagnosed post-partum hemorrhage (>500 mL vaginal birth or >1000 mL cesarean section), with a second 1 g dose if bleeding continues after 30 minutes or restarts within 24 hours. 1

• This applies to all causes of post-partum hemorrhage, including uterine atony and genital tract trauma, not just when uterotonics fail 1
• Early treatment optimizes benefits; delay reduces effectiveness by 10% for every 15 minutes 1

Surgical Applications

For cardiac surgery and elective procedures with bleeding risk: TXA 10 mg/kg loading dose followed by 1-5 mg/kg/hour infusion 1

• Alternative weight-based dosing: 10-15 mg/kg loading dose followed by 1-5 mg/kg/hour 1
• Plasma half-life is 120 minutes; therapeutic level of 10 μg/mL required to inhibit fibrinolysis 1
• Stop therapy once bleeding is adequately controlled 1

Hemophilia Patients (Dental Extraction)

Administer 10 mg/kg IV before extraction with replacement therapy, then 10 mg/kg IV 3-4 times daily for 2-8 days post-extraction. 2

• Infuse no faster than 1 mL/minute to avoid hypotension 2

Epsilon-Aminocaproic Acid (EACA)

EACA is 10-fold less potent than TXA and requires higher dosing: 100-150 mg/kg loading dose followed by 15 mg/kg/hour continuous infusion. 1

• Shorter elimination half-life (60-75 minutes) necessitates continuous infusion to maintain therapeutic levels 1
• For cardiac surgery: 15 g bolus plus 1 g/hour infusion has demonstrated efficacy 3
• Alternative regimen: 7.5 g IV boluses followed by 1-1.25 g/hour infusion 4
• TXA is at least 5-7 times more potent than EACA on a molar basis 5, 6

Key Indications

Strongly Recommended (Grade 1A-1B Evidence)

• Trauma with active bleeding or risk of significant hemorrhage (within 3 hours of injury) 1
• Post-partum hemorrhage (within 3 hours of birth) 1
• Established hyperfibrinolysis detected by thromboelastometry 1

Suggested Uses (Grade 2C Evidence)

• Cardiac surgery to reduce perioperative bleeding 4, 3, 7
• Orthopedic surgery (scoliosis, total knee arthroplasty, craniofacial procedures) 5, 8
• Tonsillectomy/adenoidectomy 8
• Prostatic surgery, cervical conization, menorrhagia 6
• Tooth extraction in hemophilia patients 2, 6

Absolute Contraindications

Do not administer TXA in the following situations:

• Subarachnoid hemorrhage (risk of cerebral edema and infarction) 2
• Active intravascular clotting/disseminated intravascular coagulation 2
• Severe hypersensitivity to tranexamic acid or ingredients 2
• More than 3 hours after traumatic injury (associated with increased mortality) 1
• Inadvertent neuraxial administration (risk of seizures) 2

Critical Safety Considerations

Thrombotic Risk

• Historical concerns about thrombosis have not been substantiated; CRASH-2 showed lower rates of myocardial infarction with TXA 1
• Cochrane review of >8,000 patients receiving lysine analogues demonstrated no increased arterial or venous thrombotic events 1
• Avoid concomitant use with Factor IX or other prothrombotic agents 2

Seizure Risk

• Increased seizure rates reported with high-dose TXA in cardiac surgery 1
• FOR INTRAVENOUS USE ONLY - inadvertent neuraxial injection may cause seizures 2

Renal Impairment

• Both TXA and EACA are renally excreted and accumulate in renal failure 1
• Reduce dosage in patients with renal impairment 2
• Mild renal impairment typically does not affect outcomes in practice 1

Other Adverse Effects

• Common: nausea, vomiting, diarrhea, dizziness, hypotension (if infused too rapidly) 2, 6
• Visual disturbances: discontinue if ocular symptoms occur 2
• Advise patients not to drive if dizziness occurs 2

Monitoring Recommendations

• Fibrinolysis monitoring via thromboelastometry is recommended when available to guide therapy 1
• However, do not delay TXA administration in trauma awaiting test results 1
• Monitor for visual changes, hypersensitivity reactions, and signs of thrombosis 2

Comparative Efficacy

TXA is preferred over EACA due to:

• 5-10 fold greater potency requiring lower doses 5, 6
• Longer half-life (120 min vs 60-75 min) allowing less frequent dosing 1
• More robust evidence base, particularly in trauma (CRASH-2 trial) 1
• In scoliosis surgery, TXA demonstrated 391 mL less blood loss compared to EACA 5

Aprotinin is no longer recommended due to increased renal disease and mortality compared to lysine analogues 1