What is the dose of tranexamic acid (TXA) for bleeding?

Tranexamic Acid Dosing for Bleeding

For trauma-related hemorrhage, administer tranexamic acid 1 gram IV over 10 minutes as a loading dose, followed by 1 gram IV infusion over 8 hours, starting as soon as possible and within 3 hours of injury. 1, 2, 3

Standard Dosing Regimen

The evidence-based protocol is:

• Loading dose: 1 gram IV over 10 minutes 1, 2, 3
• Maintenance dose: 1 gram IV infusion over 8 hours 1, 2, 3
• Critical timing: Must be administered within 3 hours of injury onset 1, 2, 3

Timing is Critical for Mortality Benefit

Time-dependent effectiveness:

• Effectiveness decreases by 10% for every 15-minute delay in administration 1, 2
• Early administration (≤1 hour from injury) provides the greatest mortality reduction from bleeding 1, 3
• Administration after 3 hours post-injury may actually increase the risk of death due to bleeding 1, 3
• Pre-hospital administration should be strongly considered to ensure treatment within the therapeutic window 1, 3

This time-critical nature is supported by the CRASH-2 trial, which demonstrated that TXA reduces hemorrhage death by approximately one-third when given within 3 hours, but this benefit is lost—and potentially reversed—beyond this window 4.

Specific Clinical Contexts

Postpartum Hemorrhage

• First dose: 1 gram IV as soon as possible after childbirth 5
• Second dose: 1 gram IV if bleeding continues after 30 minutes or restarts within 24 hours 5
• The WHO endorses this regimen based on the WOMAN trial, which showed mortality reduction with no increase in thromboembolic events 5

Traumatic Brain Injury

• Same dosing as trauma: 1 gram IV over 10 minutes, followed by 1 gram over 8 hours 1
• Benefit is particularly evident in mild to moderate traumatic brain injury when administered within 3 hours 1, 3

Renal Impairment Dosing Adjustments

For patients with renal dysfunction, dose reduction is mandatory: 6

• Serum creatinine 1.36-2.83 mg/dL: 10 mg/kg twice daily
• Serum creatinine 2.83-5.66 mg/dL: 10 mg/kg once daily
• Serum creatinine >5.66 mg/dL: 10 mg/kg every 48 hours OR 5 mg/kg every 24 hours

Alternative Routes and Dosing

Intramuscular Administration

• Current guidelines recommend IV administration only, as the WHO and European guidelines explicitly state their recommendations apply to IV route exclusively 2
• Recent research suggests that 30 mg/kg IM may achieve comparable serum concentrations to IV administration, though this is not yet incorporated into clinical guidelines 7
• The standard 15 mg/kg IM dose does not achieve adequate serum levels 7
• Clinical guidelines do not yet include specific recommendations for IM dosing 1, 2

Historical Dosing (Not Current Standard)

• European guidelines from 2007 suggested 10-15 mg/kg followed by infusion of 1-5 mg/kg per hour, but this has been superseded by the current 1 gram/1 gram protocol 1

Critical Safety Considerations

Contraindications and warnings:

• Contraindicated in active intravascular clotting 6
• Contraindicated in subarachnoid hemorrhage due to risk of cerebral edema and infarction 6
• Higher doses are associated with increased seizure risk, particularly in cardiac surgery patients 1, 3
• Seizures occurred more frequently with TXA in the HALT-IT trial (0.6% vs 0.4%) 8
• Venous thromboembolic events (DVT/PE) were increased in gastrointestinal bleeding patients (0.8% vs 0.4%), though arterial events were similar 8

Common Pitfalls to Avoid

Critical errors that reduce effectiveness or increase harm:

• Delaying administration beyond 3 hours significantly reduces effectiveness and may increase mortality 1, 2, 3
• Infusing too rapidly (>1 mL/minute) can cause hypotension 6
• Using TXA for gastrointestinal bleeding—the HALT-IT trial showed no mortality benefit and increased thromboembolic complications 8
• Mixing TXA with blood products or penicillin-containing solutions 6
• Inadvertent intrathecal administration has caused seizures and cardiac arrhythmias 6

Context-Specific Limitations

Important negative evidence:

• For gastrointestinal bleeding, a large randomized trial (HALT-IT, n=12,009) showed no mortality benefit with the high-dose regimen (1 gram loading, 3 grams over 24 hours) and increased venous thromboembolism risk 8
• This highlights that TXA's benefit is specific to trauma-related hemorrhage and cannot be uniformly applied to all bleeding contexts 8