Tranexamic Acid Dosing in Organ Transplantation
For patients undergoing organ transplantation, tranexamic acid should be administered as a 10 mg/kg loading dose followed by a 1 mg/kg/hour infusion during the procedure, with dose reductions required in patients with renal dysfunction. 1
Rationale for TXA Use in Transplantation
Tranexamic acid (TXA) is particularly valuable during liver transplantation due to the hyperfibrinolytic state that occurs during the procedure:
- Hyperfibrinolysis during liver transplantation is caused by high levels of tissue plasminogen activator release, especially during the anhepatic phase 1
- Randomized controlled trials have demonstrated that antifibrinolytic treatment reduces blood loss and transfusion requirements in liver transplantation without increasing thrombotic events 1
- TXA has replaced aprotinin (which was withdrawn due to mortality concerns in cardiac surgery) as the preferred antifibrinolytic agent for transplantation 1
Standard Dosing Protocol
The recommended dosing regimen for TXA in organ transplantation is:
- Loading dose: 10 mg/kg IV administered over 10 minutes
- Maintenance infusion: 1 mg/kg/hour during the procedure 2, 3
This dosing has been shown to significantly reduce:
- Intraoperative blood loss (median 4.3L vs 8L with placebo) 3
- Perioperative erythrocyte use (median 9 units vs 13 units) 3
- Total perioperative donor exposure (20.5 units vs 43.5 units) 3
Renal Dose Adjustments
Since TXA is primarily eliminated through renal clearance (90% excreted in urine within 24 hours), dose adjustments are mandatory in patients with renal dysfunction 1:
| Serum Creatinine | TXA IV Dosage |
|---|---|
| 1.36-2.83 mg/dL | 10 mg/kg twice daily |
| 2.83-5.66 mg/dL | 10 mg/kg daily |
| >5.66 mg/dL | 10 mg/kg every 48 hours or 5 mg/kg every 24 hours |
Failure to adjust dosing in renal dysfunction can lead to serious complications including neurotoxicity and ocular toxicity 1.
Monitoring During TXA Administration
When administering TXA during organ transplantation, monitor:
- Coagulation parameters (PT, APTT, fibrinogen) 1
- Kidney function (serum creatinine) 1
- Signs of thrombosis, especially in high-risk patients 4
- Visual disturbances, seizures, or hypersensitivity reactions 4
Special Considerations for Different Transplants
Liver Transplantation
- TXA has been extensively studied in liver transplantation and shown to be effective 3, 5
- High-dose TXA (up to 20g total) has been used safely in liver transplantation studies 3
- No increased risk of hepatic artery or portal venous thrombosis has been observed with proper dosing 3
Kidney Transplantation
- More cautious dosing is required due to the recipient's compromised renal function
- Follow renal dosing adjustments strictly 1
- Monitor serum creatinine frequently as recommended by KDIGO guidelines 1
Contraindications and Cautions
TXA should be avoided or used with extreme caution in transplant patients with:
- Active intravascular clotting
- Subarachnoid hemorrhage
- Hypersensitivity to TXA
- History of seizures (TXA can lower seizure threshold)
- Massive hematuria (risk of ureteric obstruction) 4
Efficacy Comparison
TXA has been shown to be superior to:
- Epsilon-aminocaproic acid for reducing packed red blood cell usage during liver transplantation 5
- Placebo in multiple studies 3, 5
The evidence strongly supports that proper TXA administration significantly reduces blood loss and transfusion requirements without increasing thrombotic complications in organ transplantation.