How can you monitor and adjust treatment with vitamin K antagonists?
Anticoagulant (blood-thinning) medications like vitamin K antagonists are used to prevent blood clots. This can lower the risk of certain cardiovascular (heart and blood vessel) diseases, especially strokes. The medication is often prescribed for people who have an irregular heartbeat like atrial fibrillation or flutter, and for people who have an artificial heart valve. Vitamin K antagonists are also used by people who have deep vein thrombosis or pulmonary (lung) embolism – to treat it, and sometimes to prevent further blood clots as well.
Vitamin K antagonists are sometimes called coumarins. The most commonly used vitamin K antagonist in Germany is phenprocoumon. It is best known under the trade name Marcumar, but also as Falithrom and Phenprogamma. Warfarin is the most widely prescribed anticoagulant in some other countries.
These medications slow down the blood-clotting process. The clotting ability of the blood has to be monitored regularly in order to adjust the dose: It should be high enough to prevent blood clots – but low enough to minimize the risk of serious bleeding.