[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Antifibrinolytic haemostatics](https://durgical.com/en/pharmacology/classes/antifibrinolytic-haemostatics/) › Tranexamic acid

[Pharmacology](https://durgical.com/en/pharmacology/) · [Antifibrinolytic haemostatics](https://durgical.com/en/pharmacology/classes/antifibrinolytic-haemostatics/)

# Tranexamic acid

A lysine analogue that blocks clot breakdown. WHO recommends it for postpartum haemorrhage; it is also used in trauma, surgery and heavy periods.

Updated 2026-11-01

- Class: [Antifibrinolytic haemostatics](https://durgical.com/en/pharmacology/classes/antifibrinolytic-haemostatics/)
- Target: Lysine-binding sites (kringle domains) of plasminogen
- ATC code: B02AA02
- WHO Model List of Essential Medicines

Also called: TXA

◆**Lysine-binding sites (kringle domains) of plasminogen**Tranexamic acid

ⓘ The figure shows tranexamic acid (trans-4-aminomethylcyclohexane-1-carboxylic acid) bound in the lysine-binding pocket of kringle 1 of human plasminogen.

**Target in 3D:** Lysine-binding sites (kringle domains) of plasminogen. PDB structure 1CEB (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/1CEB) · Drag to rotate · pinch to zoom

## Mechanism of action

Tranexamic acid is a synthetic lysine analogue. It occupies the lysine-binding sites on plasminogen and plasmin, so they can no longer attach to fibrin. Fibrinolysis slows down and the clots that form at a bleeding site last longer. It does not activate coagulation.

- Plasminogen binds fibrin through its lysine-binding sites
- The drug, a lysine analogue, occupies those sites
- Plasminogen and plasmin cannot attach to fibrin
- The clot is protected from early breakdown

## Pharmacokinetics

**Absorption**
Given intravenously or by mouth

**Distribution**
Crosses the placenta; cord blood levels are similar to the mother's

**Elimination**
Kidneys, almost entirely unchanged; lower doses are used in renal impairment

**Half-life**
About 2 hours (terminal phase)

## Indications

- Treatment of postpartum haemorrhage, together with standard obstetric care (WHO recommendation) [Postpartum haemorrhage →](https://durgical.com/en/conditions/postpartum-haemorrhage/)
- Major trauma with bleeding, during resuscitation [Major trauma (polytrauma): ATLS primary survey →](https://durgical.com/en/conditions/major-trauma-atls-primary-survey/)
- Heavy menstrual bleeding (tablets) [Abnormal uterine bleeding →](https://durgical.com/en/conditions/abnormal-uterine-bleeding/)
- Haemophilia, to reduce bleeding around tooth extraction [Haemophilia A and B →](https://durgical.com/en/conditions/haemophilia-a-and-b/)
- Reducing blood loss in surgery such as hip or knee replacement or cardiac surgery

## Adverse effects

### Common

- Nausea, vomiting, diarrhoea
- Dizziness
- Visual disturbances

### Serious (rare, important)

- Venous and arterial thrombosis or thromboembolism
- Seizures, especially at high doses in cardiac surgery or after neuraxial injection by mistake
- Hypersensitivity, including anaphylaxis

## Contraindications

- Neuraxial (intrathecal or epidural) injection
- Subarachnoid haemorrhage
- Active intravascular clotting
- Hypersensitivity to tranexamic acid

## Key interactions

**Hormonal contraceptives**
Together they raise the risk of thrombosis

**Factor IX complex and anti-inhibitor coagulant concentrates**
Pro-thrombotic products; the combination increases thrombosis risk

## What is monitored

- Bleeding and haemoglobin
- Kidney function
- Signs of thrombosis (leg swelling, chest pain, neurological deficit)
- Vision; it is stopped if visual symptoms appear

## Administration and safety

- The injection is for intravenous use only; fatal reactions have followed accidental intrathecal injection
- Label syringes with the drug and route; keep it apart from local anaesthetics and other solutions used at the same time
- Given slowly intravenously; rapid injection can cause hypotension

## Nursing care

- In postpartum haemorrhage, give it alongside uterotonics and the other steps of the protocol and record the time
- Check the route before every injection, especially in obstetric and spinal anaesthesia settings
- Watch for seizures, visual changes and signs of thrombosis
- Check kidney function before repeated doses

## Pregnancy and breastfeeding

It crosses the placenta; it is used in pregnancy and childbirth when the benefit justifies it, and WHO recommends it for postpartum haemorrhage.

## Memory aid

TXA = «Traffic eXit Arrested»: plasmin cannot exit onto fibrin, so the clot stays.

## Test yourself

Think of the answer, then tap the question to see it.

## How does tranexamic acid reduce bleeding?

It blocks the lysine-binding sites of plasminogen, so plasmin cannot break down fibrin.

## Which obstetric emergency has a WHO recommendation for it?

Postpartum haemorrhage.

## Which route error is dangerous?

Neuraxial (intrathecal or epidural) injection: seizures, arrhythmias and death.

## Why is the dose lowered in kidney failure?

It is excreted almost entirely unchanged in urine.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/tranexamic-acid/)

## Related drugs

- [Aminocaproic acid](https://durgical.com/en/pharmacology/aminocaproic-acid/)
- [Alteplase](https://durgical.com/en/pharmacology/alteplase/)

## Related conditions

- [Postpartum haemorrhage](https://durgical.com/en/conditions/postpartum-haemorrhage/)
- [Major trauma (polytrauma): ATLS primary survey](https://durgical.com/en/conditions/major-trauma-atls-primary-survey/)
- [Abnormal uterine bleeding](https://durgical.com/en/conditions/abnormal-uterine-bleeding/)
- [Haemophilia A and B](https://durgical.com/en/conditions/haemophilia-a-and-b/)

[← Back to the class: Antifibrinolytic haemostatics](https://durgical.com/en/pharmacology/classes/antifibrinolytic-haemostatics/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [DailyMed - TRANEXAMIC ACID injection, solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6f033f1e-8c78-4c87-b870-6493944315ff) (DailyMed (U.S. National Library of Medicine), 2026); [WHO recommendation on tranexamic acid for the treatment of postpartum haemorrhage](https://www.who.int/publications/i/item/9789241550154) (World Health Organization, 2017); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 36 (McGraw Hill, 2023); [Tranexamic Acid: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a612021.html) (MedlinePlus (U.S. National Library of Medicine), 2017).

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Representative model, for educational purposes only.

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