From the Guidelines
Tranexamic acid (TXA) works by preventing blood clots from breaking down, which helps control bleeding, and it is recommended to be administered as early as possible, ideally within 3 hours of bleeding onset, at a dose of 1 gram intravenously over 10 minutes, followed by another 1 gram over 8 hours for trauma patients. The medication functions as an antifibrinolytic agent by binding to plasminogen and blocking its conversion to plasmin, the enzyme responsible for dissolving blood clots, as stated in the study published in Anaesthesia 1. By inhibiting this process, TXA stabilizes existing clots and prevents excessive bleeding. Some key points to consider when using TXA include:
- TXA is most effective when given early, ideally within 3 hours of bleeding onset, as demonstrated in trauma cases, and supported by the study published in Critical Care 1.
- The medication works locally at bleeding sites rather than causing widespread clotting throughout the body, which helps minimize the risk of unwanted blood clots.
- Side effects are generally mild but can include nausea, vomiting, and rarely, seizures or thrombotic events, particularly in patients with risk factors for clotting disorders.
- A meta-analysis of 216 trials found no evidence of an increased risk of thromboembolic complications associated with the use of tranexamic acid, supporting the general safety of the drug, as reported in the study published in Anaesthesia 1.
- The World Health Organization strongly recommends early use of intravenous tranexamic acid for the treatment of post-partum haemorrhage, with a fixed dose of 1 g intravenously at 1 mL/min, as stated in the study published in The Lancet Global Health 1.
From the FDA Drug Label
Tranexamic acid is a synthetic lysine amino acid derivative, which diminishes the dissolution of hemostatic fibrin by plasmin. In the presence of tranexamic acid, the lysine receptor binding sites of plasmin for fibrin are occupied, preventing binding to fibrin monomers, thus preserving and stabilizing fibrin’s matrix structure The antifibrinolytic effects of tranexamic acid are mediated by reversible interactions at multiple binding sites within plasminogen.
Tranexamic acid (TXA) works by inhibiting fibrinolysis, which is the process of breaking down blood clots. It does this by:
- Occupying lysine receptor binding sites on plasmin, preventing it from binding to fibrin monomers
- Preserving and stabilizing fibrin's matrix structure, which helps to maintain the blood clot
- Mediating reversible interactions at multiple binding sites within plasminogen, which is involved in the formation of plasmin 2
From the Research
Mechanism of Action
- Tranexamic acid (TXA) is an antifibrinolytic agent that acts by binding to plasminogen and blocking the interaction of plasmin(ogen) with fibrin, thereby preventing dissolution of the fibrin clot 3.
- This mechanism of action allows TXA to reduce blood loss in various surgical procedures and conditions with abnormal bleeding or bleeding tendencies.
Clinical Applications
- TXA is indicated in conditions such as heavy menstrual bleeding, postpartum haemorrhage, bleeding irregularities caused by contraceptive implants, and traumatic hyphaema 3, 4.
- It is also effective in reducing blood loss in orthopaedic surgery, including joint replacement, fracture surgery, and arthroscopic procedures 5, 6.
- TXA has been shown to reduce all-cause mortality and death due to bleeding in trauma patients with significant bleeding, particularly when administered early after injury 3.
Safety and Efficacy
- TXA is generally well tolerated, with most adverse events in clinical trials being of mild or moderate severity 3.
- The risk of thromboembolic events associated with TXA use is not supported by evidence, and it has been shown to be safe in a wide variety of orthopaedic procedures 5, 6.
- TXA is a cost-effective treatment for trauma patients across a variety of economic settings 6.