Acute Medical Emergencies

Question 1

Tranexamic Acid: Mechanism of Action

Answer 1

Tranexamic acid is a synthetic analog of the amino acid lysine. It serves as an antifibrinolytic by reversibly binding four to five lysine receptor sites on plasminogen. This prevents plasmin (antiplasmin) from binding to and degrading fibrin and preserves the framework of fibrin’s matrix structure.

Question 2

Tranexamic Acid: Effects/ Clinical Use

Answer 2

Major Haemorrhage

also obstetric bleedingMenorrhagia and hereditary angioedema

Question 3

Tranexamic Acid: Side Effects

Answer 3

Diarrhoea (reduce dose); nausea; vomiting

Rarely seizure at high doses

Question 4

Tranexamic Acid: Contraindications/ Cautions

Answer 4

Fibrinolytic conditions following disseminated intravascular coagulation (unless predominant activation of fibrinolytic system with severe bleeding); history of convulsions; thromboembolic disease

Massive haematuria (avoid if risk of ureteric obstruction); patients receiving oral contraceptives (increased risk of thrombosis)

Question 5

Tranexamic Acid: Dose

Answer 5

Initially by slow intravenous injection

Loading dose 1 g to be given over 10 minutes, treatment should commence within 8 hours of injury, followed by (by intravenous infusion) 1 g to be given over 8 hours.