Anticoagulation with vitamin K antagonists
(Marcoumar, Sintrom)

>> How is anticoagulant therapy monitored?
>> Do I have to discontinue anticoagulation before surgery or tooth extractions?
>> Are there alternatives to vitamin K antagonists?

How is anticoagulant therapy monitored?

Treatment with vitamin K antagonists is monitored by measurement of INR at regular intervals. The therapeutic range is between INR 2 and 3. INR values above 3 are associated with an increased bleeding risk, INR values below 2 with an increased risk of thrombosis.

Do I have to discontinue anticoagulation before surgery or tooth extractions?

In order to avoid bleeding complications, vitamin K antagonist therapy has to be discontinued prior to surgery. In patients undergoing tooth extractions or minor surgery anticoagulant treatment should be continued. If vitamin K antagonists have to be discontinued, patients at high risk of venous thromboembolism need to be protected by administration of a low molecular weight heparin.

Are there alternatives to vitamin K antagonists?

During the last years, new anticoagulants, which could replace the vitamin K antagonists in the near future, have been developed. The most advanced substances are dabigatran (Pradaxa) and rivaroxaban (Xarelto). Dabigatran and rivaroxaban are already in use for thromboprophylaxis in patients undergoing orthopaedic surgery. Both dabigatran and rivaroxaban are given orally and laboratory monitoring is no longer necessary thromboprophylaxis among patients with atrial fibrillation one of these drugs (Pradaxa) is already available and licensed in the European Union.