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Antifibrinolytic — Vascular / Surgical Haemostasis Pregnancy: Women of childbearing potential have to use effective contraception during treatment. Available data from published studies, case series and case reports in the second and third trimester and at the time of delivery have not clarified whether there is a drug-associated risk of miscarriage or adverse maternal or foetal outcomes; there are cases of foetal structural abnormalities resulting in death of the newborn following administration around conception or in the first trimester, though confounding factors mean the risk of major birth defects is not clear. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. Tranexamic acid passes through the placenta: the concentration in cord blood after an intravenous injection of 10 mg/kg to pregnant women is about 30 mg/L, as high as in maternal blood. Foetal and neonatal functional issues (low Apgar score, neonatal sepsis, cephalohaematoma) and growth alterations (low birth weight, preterm birth at 22 to 36 weeks) have been described in clinical studies of in-utero exposure. Breast-feeding: present in human milk with limited data; no final assessment can be established on use during breast-feeding. Fertility: no clinical data; animal studies show no effect on male or female fertility at clinically relevant doses. An accurate risk-benefit evaluation should drive the treating physician's decision.

Tranexamic Acid

Brand names: Cyklokapron, Femstrual (topical)

Tranexamic acid is an antifibrinolytic given orally or intravenously to prevent and treat bleeding, including in major trauma, surgery, postpartum haemorrhage and menorrhagia.

Adult dose

Dose: Haemorrhage due to local or general fibrinolysis (the licensed indication; it includes bleeding in thoracic, abdominal and other major surgery such as cardiovascular surgery). LOCAL fibrinolysis: 0.5 g to 1 g by slow intravenous injection or infusion, two to three times daily. GENERAL fibrinolysis: 1 g by slow intravenous injection or infusion every 6 to 8 hours (equivalent to 15 mg/kg body weight). 'Unless otherwise prescribed.'
Route: Intravenous only - slow intravenous injection or infusion, maximum 1 mL per minute. Must not be given intramuscularly, intrathecally or epidurally.
Frequency: Local fibrinolysis: two to three times daily. General fibrinolysis: every 6 to 8 hours.
SOURCE: UK SPC, Cyklokapron 100 mg/mL solution for injection/infusion (eMC product 1077). Section 4.1: prevention and treatment of haemorrhages due to general or local fibrinolysis in adults and children from one year, including menorrhagia and metrorrhagia, gastrointestinal bleeding, haemorrhagic urinary disorders after prostate or urinary-tract surgery, ENT surgery, gynaecological and obstetric disorders, thoracic and abdominal surgery and other major surgery such as cardiovascular surgery, and haemorrhage due to a fibrinolytic agent. These two regimens are the only adult regimens in the retrieved section 4.2: the SPC gives no separate peri-operative, trauma, oral or topical regimen, and prints NO maximum daily dose, so none is stated here. This source covers the intravenous product only; no dose is given for oral or topical tranexamic acid products. Units: 0.5 g and 1 g are absolute single doses; 15 mg/kg is the SPC's own per-kg equivalent of the 1 g dose, not an additional dose. Elderly: 'No reduction in dosage is necessary unless there is evidence of renal failure.' Safety: 'TRANEXAMIC ACID SHOULD ONLY BE ADMINISTERED INTRAVENOUSLY and should not be administered intrathecally or epidural'; to reduce the risk of fatal medication errors from the wrong route, label syringes containing tranexamic acid. DIC (section 4.4): 'In such acute cases a single dose of 1 g tranexamic acid is frequently sufficient to control bleeding.'

Paediatric dose

Dose: 20 mg/kg/day
Route: Intravenous only (slow injection or infusion, maximum 1 mL per minute)
Frequency: The SPC gives a daily total and does not state how it is divided
Concentration: 100 mg/ml
SPC section 4.2: 'In children from 1 year, for current approved indications as described in section 4.1, the dosage is in the region of 20 mg/kg/day. However, data on efficacy, posology and safety for these indications are limited. The efficacy, posology and safety of tranexamic acid in children undergoing cardiac surgery have not been fully established.' The 100 mg/mL strength is the product strength (Cyklokapron 100 mg/mL). This is a DAILY figure - never give it as a single dose. Verify any paediatric use against a children's formulary.

Dose adjustments

Renal

Dose is reduced by serum creatinine (SPC section 4.2): creatinine 120 to 249 micromol/L (1.35 to 2.82 mg/dL) - 10 mg/kg body weight every 12 hours; 250 to 500 micromol/L (2.82 to 5.65 mg/dL) - 10 mg/kg body weight every 24 hours; above 500 micromol/L (above 5.65 mg/dL) - 5 mg/kg body weight every 24 hours. Elderly: no reduction in dosage is necessary unless there is evidence of renal failure.

Hepatic

No dose adjustment is required in patients with hepatic impairment.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Paediatric weight-based calculator

SPC section 4.2: 'In children from 1 year, for current approved indications as described in section 4.1, the dosage is in the region of 20 mg/kg/day. However, data on efficacy, posology and safety for these indications are limited. The efficacy, posology and safety of tranexamic acid in children undergoing cardiac surgery have not been fully established.' The 100 mg/mL strength is the product strength (Cyklokapron 100 mg/mL). This is a DAILY figure - never give it as a single dose. Verify any paediatric use against a children's formulary.

Verify in a children's formulary

Contraindications

  • Hypersensitivity to the active substance or to any of the excipients
  • Acute venous or arterial thrombosis
  • Fibrinolytic conditions following consumption coagulopathy, except in those with predominant activation of the fibrinolytic system with acute severe bleeding
  • History of convulsions
  • Intrathecal, epidural, intraventricular injection and intracerebral application (risk of cerebral oedema, convulsions and death)

Side effects

  • Hypersensitivity reactions including anaphylaxis
  • Convulsions, particularly in case of misuse; in CABG surgery most cases followed high intravenous doses
  • Visual disturbances including impaired colour vision
  • Malaise with hypotension, with or without loss of consciousness (generally following a too fast intravenous injection)
  • Arterial or venous thrombosis at any site
  • Diarrhoea, vomiting, nausea
  • Allergic dermatitis
  • Inadvertent intrathecal administration has caused severe back, gluteal and lower limb pain, myoclonus, generalised seizures, cardiac arrhythmias and fatal events

Interactions

  • Anticoagulants: simultaneous treatment must take place under the strict supervision of a physician experienced in this field
  • Medicinal products that act on haemostasis should be given with caution to patients treated with tranexamic acid
  • Hormonal contraception: increased thrombus-formation potential; use with care
  • The antifibrinolytic action may be antagonised by thrombolytic drugs
  • No interaction studies have been performed (SPC section 4.5)

Monitoring

  • Injection rate - give very slowly (maximum 1 mL per minute); too-fast injection causes malaise with hypotension
  • Route check before every dose - label syringes with the intravenous route; be alert to confusion with other injectables used in the same procedure
  • Serum creatinine - the dose is reduced by creatinine band
  • Visual disturbances - attend to any visual impairment, blurred vision or impaired colour vision and discontinue if necessary; with continuous long-term use, regular ophthalmologic examinations (visual acuity, colour vision, fundus, visual field)
  • Haematuria from the upper urinary tract - risk of urinary obstruction at lower levels; close monitoring for patients with haematuria or at risk of it
  • Consider thromboembolic risk factors before use; in patients with a history of thromboembolic disease or a family history (high risk of thrombophilia), use only with a strong medical indication, after consulting a physician experienced in haemostaseology and under strict medical supervision
  • DIC: in most cases do not treat; if given, restrict to those with predominant activation of the fibrinolytic system with acute severe bleeding, and only where appropriate haematological laboratory facilities and expertise are available

Clinical monograph

How it works

It competitively blocks the lysine-binding sites on plasminogen, preventing its conversion to plasmin and so inhibiting fibrinolysis and stabilising formed clots.

Prescribing in practice

  • Avoid in active thromboembolic disease and use with caution where there is a history of venous or arterial thrombosis, since inhibiting clot breakdown can promote thrombosis; in trauma it should be given early as benefit falls with delay.
  • Intravenous injection should be given slowly to limit hypotension, and the dose must be reduced in renal impairment because the drug is renally cleared and can accumulate.
  • It is contraindicated in a history of convulsions and in subarachnoid haemorrhage outside specialist protocols, and accidental intrathecal administration can cause seizures and death.

Monitoring

Monitor for signs of thromboembolism and, with prolonged treatment, consider eye examinations for visual disturbance; assess renal function to guide dosing.

Counselling the patient

  • For heavy periods, take only during bleeding days as directed.
  • Report leg swelling or pain, chest pain or breathlessness.
  • Stop and seek advice if you develop visual disturbance on long-term use.

Evidence & guidelines

Its survival and bleeding benefits are supported by the CRASH-2 and WOMAN trials and endorsed in NICE trauma and major haemorrhage guidance.

Reference: CRASH-2 Trial 2010; WOMAN Trial 2017; POISE-3 Trial 2022; NICE NG24 (Major Trauma); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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