Measuring Oral Direct Inhibitors (ODIs) of thrombin and factor Xa: A recommendation from the Subcommittee on Control of Anticoagulation of the Scientific and Standardisation Committee of the International Society on Thrombosis and Haemostasis.

Oral direct inhibitors (ODIs) of thrombin and factor Xa are now approved as anticoagulant drugs. The first two drugs to complete phase III clinical trials for thromboprophylaxis in orthopaedic surgery and treatment of patients with atrial fibrillation or venous thromboembolism were dabigatran and rivaroxaban. These small molecules are given at fixed dose with no requirement for monitoring as pharmacokinetic and pharmacodynamic responses are reliably predicted in patients with adequate renal function who are not taking other interacting drugs. However, there will be clinical circumstances in specific patients when measurement of the anticoagulant effect of an ODI will be required.