Dabigatran etexilate: a new thrombin inhibitor

Dabigatran etexilate was recently approved by the Therapeutic Goods Administration for thromboprophylactic use in adults undergoing elective total hip or knee replacement. Dabigatran etexilate is the prodrug of the active moiety dabigatran, an orally active agent that could replace enoxaparin in some clinical indications. Dabigatran is a direct thrombin inhibitor; it has stable, predictable pharmacokinetics and does not require routine monitoring. Pooled efficacy data from large-scale phase III clinical trials of dabigatran use in orthopaedic thromboprophylaxis have shown non-inferiority to enoxaparin, with total venous thromboembolism results of 3.8% for dabigatran etexilate 150 mg and 3.0% for dabigatran etexilate 220 mg, compared with 3.3% for enoxaparin. Pooled safety results for dabigatran are similar to those for enoxaparin, with major bleeding rates of 1.1% for dabigatran etexilate 150 mg and 1.4% for dabigatran etexilate 220 mg, compared with 1.4% for enoxaparin. Dabigatran failed to demonstrate non-inferiority compared with enoxaparin 30 mg twice daily for orthopaedic thromboprophylaxis. Issues relating to the use of dabigatran include its lack of antidote, limited application in renal disease, and interaction with drugs such as amiodarone and verapamil. Several trials investigating the use of dabigatran for other indications, such as stroke prevention in atrial fibrillation and acute coronary syndromes, are underway. Given its safety profile, efficacy, oral bioavailability and stable pharmacokinetic properties, dabigatran may be a viable alternative to enoxaparin for thromboprophylaxis in orthopaedic surgery.