Tranexamic acid - A review of its use in surgery and other indications

Tranexamic acid is a synthetic derivative of the amino acid lysine that exe rts its antifibrinolytic effect through the reversible blockade of lysine b inding sites on plasminogen molecules. Intravenously administered tranexamic acid (most commonly 10 mg/kg followed by infusion of 1 mg/kg/hour) caused reductions relative to placebo of 29 t o 54% in postoperative blood losses in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB), with statistically significant reduction s in transfusion requirements in some studies, Tranexamic acid had similar efficacy to aprotinin 2 x 10(6) kallikrein inhibitory units (KIU) and was s uperior to dipyridamole in the reduction of postoperative blood losses. Tra nsfusion requirements were reduced significantly by 43% with tranexamic aci d and by 60% with aprotinin in 1 study. Meta-analysis of 60 trials showed t ranexamic acid and aprotinin, unlike E-aminocaproic acid (EACA) and desmopr essin, to reduce significantly the number of patients requiring allogeneic blood transfusions after cardiac surgery with CPB, Tranexamic acid was associated with reductions relative to placebo in morta lity of 5 to 54% in patients with upper,gastrointestinal bleeding, Meta-ana lysis indicated a reduction of 40%. Reductions of 34 to 57.9% versus placebo or control in mean menstrual blood loss occurred during tranexamic acid therapy in women with menorrhagia; th e drug has also been used to good effect in placental bleeding, postpartum haemorrhage and conisation of the cervix, Tranexamic acid significantly red uced mean blood losses after oral surgery in patients with haemophilia and was effective as a mouthwash in dental patients receiving oral anticoagulan ts. Reductions in blood loss were also obtained with the use of the drug in pat ients undergoing orthotopic liver transplantation or transurethral prostati c surgery, and rates of rebleeding were reduced in patients with traumatic hyphaema, Clinical benefit has also been reported with tranexamic acid in p atients with hereditary angioneurotic oedema, Tranexamic acid is well tolerated; nausea and diarrhoea are the most common adverse events. Increased risk of thrombosis with the drug has not been de monstrated in clinical trials. Conclusions: Tranexamic acid is useful in a wide range of haemorrhagic cond itions. The drug reduces postoperative blood losses and transfusion require ments in a number of types of surgery, with potential cost and tolerability advantages over aprotinin, and appears to reduce rates of mortality and ur gent surgery in patients with upper gastrointestinal haemorrhage. Tranexami c acid reduces menstrual blood loss and is a possible alternative to surger y in menorrhagia, and has been used successfully to control bleeding in pre gnancy.