Adult: Local fibrinolysis: 500-1,000 mg 2-3 times daily. General fibrinolysis: 1,000 mg (or 15 mg/kg) 6-8 hourly. Doses are administered via slow inj at a rate no more than 100 mg/min.
Intravenous Patients with haemophilia undergoing dental extraction
Adult: 10 mg/kg as a single dose via slow inj at a rate no more than 100 mg/min immediately before tooth extraction, followed by 10 mg/kg 3-4 times daily for 2-8 days.
Oral Menorrhagia
Adult: 1,000 mg tid during menstruation as necessary for up to 4 days, may be increased for heavy bleeding. Max: 4,000 mg daily. Alternatively, 1,300 mg tid during menstruation for up to 5 days.
Oral Hereditary angioedema
Adult: 1,000-1,500 mg 2-3 times daily given intermittently or continuously, depending on patient condition.
Oral Haemorrhage
Adult: As short-term management of localised cases: 1,000-1,500 mg (or 15-25 mg/kg) 2-3 times daily.
Oral Patients with haemophilia undergoing dental extraction
Adult: 1,000-1,500 mg (or 25 mg/kg) 8 hourly.
Renal Impairment
Oral: Haemorrhage; Hereditary angioedema; Patients with haemophilia undergoing dental extraction:
Mild to moderate: Serum creatinine level (micromole/L): 120-249 micromole/L: 15 mg/kg bid; 250-500 micromole/L: 15 mg/kg once daily. Severe: Contraindicated.
Oral: Menorrhagia:
Mild to moderate: Serum creatinine level (micromole/L): 120-249 micromole/L: 15 mg/kg or 1,300 mg bid; 250-500 micromole/L: 15 mg/kg or 1,300 mg once daily. Severe: Contraindicated.
Intravenous:
Incompatible with benzylpenicillin and blood for transfusion.
Contraindications
Hypersensitivity. Active thromboembolic disease (e.g. pulmonary embolism, DVT, cerebral thrombosis), history or risk of thromboembolism (including retinal vein or artery occlusion); fibrinolytic conditions after consumption coagulopathy (unless predominant activation of the fibrinolytic system with acute severe bleeding), history of convulsions; acquired disturbances of colour vision. Severe renal impairment. Concomitant use with combined hormonal contraceptives.
Special Precautions
Patient with massive haematuria from the upper urinary tract, uncorrected CV or cerebrovascular disease, subarachnoid haemorrhage. Women with irregular menstrual cycle; not for use prior to menarche or post-menopause. Not recommended for use in patients with acute promyelocytic leukaemia taking oral tretinoin. Mild to moderate renal impairment. Pregnancy and lactation.
Adverse Reactions
Significant: Visual defects (e.g. changes in colour vision, visual loss), retinal venous and arterial occlusions, ligneous conjunctivitis; convulsions (particularly with high doses of IV inj), severe hypersensitivity reactions (e.g. anaphylaxis or anaphylactoid reaction), venous and arterial thrombosis or thromboembolism; cerebral oedema and infarction (particularly in women with subarachnoid haemorrhage), dizziness. Blood and lymphatic system disorders: Anaemia. Gastrointestinal disorders: Nausea, vomiting, diarrhoea, abdominal pain. General disorders and administration site conditions: Fatigue. Musculoskeletal and connective tissue disorders: Musculoskeletal pain, back pain, muscle cramps or spasm, arthralgia. Nervous system disorders: Headache, migraine. Respiratory, thoracic and mediastinal disorders: Nasal and sinus symptoms. Skin and subcutaneous tissue disorders: Allergic dermatitis.
This drug may cause dizziness, if affected, do not drive or operate machinery.
Monitoring Parameters
Perform eye examinations (e.g. visual acuity, intraocular pressure, visual fields, slit lamp) and monitor LFTs regularly during continuous long-term treatment. Monitor for signs and symptoms of hypersensitivity reactions, convulsions, thrombotic events, and ureteral obstruction. For menorrhagia: Exclude structural or histological causes or fibroids distorting the uterine cavity before initiating treatment.
Overdosage
Symptoms: Nausea, vomiting, diarrhoea, dizziness, headache, orthostatic symptoms and/or hypotension, convulsions, mental status changes, rash, visual impairment, myoclonus, and thromboembolic events. Management: Supportive and symptomatic treatment. Induce vomiting, followed by stomach lavage and charcoal therapy. Maintain high fluid intake to promote excretion. Consider anticoagulant treatment.
Drug Interactions
May exacerbate the procoagulant effects of oral tretinoin in patients with acute promyelocytic leukaemia. Increased risk of thrombosis with factor IX complex concentrates or anti-inhibitor coagulant concentrates; avoid concomitant use. Concomitant use of tranexamic acid with tissue plasminogen activators may reduce the efficacy of both drugs. Potentially Fatal: May further increase the risk of venous thromboembolism or arterial thrombosis (e.g. MI, stroke) with combined hormonal contraceptives.
Action
Description: Mechanism of Action: Tranexamic acid is an antifibrinolytic agent that inhibits the breakdown of fibrin clots. It blocks the lysine binding sites of plasminogen and impairs the endogenous fibrinolytic process, thus preserving and stabilising the fibrin matrix structure. Additionally, it reduces inflammation associated with hereditary angioedema by inhibiting the proteolytic activity of plasmin which decreases the activation of complement and consumption of C1 esterase inhibitor (C1-INH). Pharmacokinetics: Absorption: Absorbed from the gastrointestinal tract. Bioavailability: Approx 45% (oral). Time to peak plasma concentration: Approx 3 hours (oral). Distribution: Widely distributed throughout the body. Crosses the placenta and enters breast milk. Volume of distribution: 9-12 L (IV). Plasma protein-binding: Approx 3%, mainly to plasminogen. Metabolism: Only a small fraction is metabolised. Excretion: Via urine (>95% as unchanged drug). Elimination half-life: Approx 11 hours (oral); approx 2 hours (IV).