[New anticoagulants. Characteristics, monitoring and management of bleeding]

Vitamin K antagonists and heparins have been standard anticoagulation drugs over the past decades. They are effective and safe but they have several drawbacks which has led to the development of new oral anticoagulants. Dabigatran etexilate is a specific oral thrombin inhibitor and rivaroxaban and apixaban are oral inhibitors of factor Xa. These agents produce a predictable anticoagulant response after fixed-dose administration so that routine coagulation monitoring is unnecessary. Currently, dabigatran etexilate, rivaroxaban and apixaban are licensed for thromboprophylaxis after elective total hip or knee replacement surgery. Since august 2011, dabigatran etexilate is licensed for patients with atrial fibrillation, rivaroxaban will follow. However, indications will be expanded e.g. for therapy of venous thromboembolism. It is important to be aware of the pharmacokinetic and pharmacodynamic profiles of these new agents. The drugs considerably influence the global test of coagulation thus making an interpretation of test results difficult. Currently, there is a lack of suitable coagulation tests to monitor anticoagulation in emergency cases, such as bleeding. Specific antidotes are not yet available.