New oral anticoagulants to revolutionise venous thromboembolism (VTE) management

Summary 

Warfarin, a vitamin K antagonist has been the mainstay of venous thromboembolism treatment for over 60years. However, it has significant limitations in relation to achieving a safe and therapeutic efficacy. Evolution in the development of oral anticoagulants to offset the drawbacks of warfarin, has led to the introduction of two new oral anticoagulants, namely dabigatran, a direct thrombin inhibitor and rivaroxaban, a direct factor Xa inhibitor. This paper examines the potential of the two new oral anticoagulants to offer a safer therapeutic alternative to warfarin, as well as their clinical efficacy in relation to the prevention of venous thromboembolism in patients undergoing hip and knee replacement surgery. In seven randomized clinical trials, dabigatran has demonstrated noninferior efficacy to enoxaparin, with a similar safety profile. Following a single technology appraisal of dabigatran, The National Institute of Clinical Excellence (NICE) have now endorsed its clinical efficacy as a serious alternative to low molecular weight heparin and fondaparinux.

Three randomized clinical trials have also concluded that rivaroxaban is as efficacious and safe as enoxaparin in the prevention of venous thromboembolism for patients undergoing major orthopaedic surgery of the lower limbs. In a single technology appraisal, rivaroxaban within its marketing authorisation was recommended by NICE in April 2009, as an option for the prevention of venous thromboembolism in adults having elective hip or knee replacement surgery.

Keywords: Blood clotting cascade, Direct thrombin inhibitors, Deep vein thrombosis, Venous thromboembolism, Oral anticoagulant, Warfarin, Ximelagatran, Dabigatran etexilate, Rivaroxaban, Low molecular weight heparin, Enoxaparin, Direct factor Xa inhibitor