ANTICOAGULANTS — A COMPREHENSIVE REVIEW

Masoud Kiani, Pankevych A. I.

LITERATURE REVIEWS

Scentific article

Anticoagulants are often called "blood thinners". They help prevent blood clots from forming and growing and reduce risk for stroke, heart attack and blockages in arteries and veins. They cannot, however, break up blood clots that are already formed. Anticoagulants help prevent blood clots and are often taken by people who have artificial heart valves, have atrial fibrillation (irregular heartbeat), have had a heart attack or have other heart diseases, such as cardiomyopathy, that increase the risk of developing blood clots. Although they are often called blood thinners, anticoagulants do not really thin blood, but decrease its ability to clot (coagulate). Reducing the likelihood of clotting means fewer harmful blood clots will form so that they do not potentially block blood vessels, causing a heart attack or stroke. Anticoagulants are available in several forms and they can be taken as tablets or given by injection or intravenously. Because anticoagulants delay clotting, their major side effect is unwanted bleeding. Anticoagulants inhibit the production of thrombin (an enzyme or catalytic molecule, that helps in the formation of fibrin) and the formation of fibrin (the material that makes up the matrix of clots). The main varieties of anticoagulants include heparin, low molecular weight heparins such as dalteparin (brand name Fragmin) and enoxaparin (Lovenox) and coumarins (vitamin K antagonists) such as warfarin (Coumadin) and dicumarol. Heparin and low molecular weight heparins are given by injection and are usually used as short term therapy. Coumarins, which are mostly pills (warfarin is also available as an injection), are used for longer term therapy. Anticoagulants remain the primary strategy for the prevention and treatment of thrombosis. Unfractionated heparin, low molecular weight heparin, fondaparinux, and warfarin have been studied and employed extensively with direct thrombin inhibitors typically reserved for patients with complications or those requiring intervention. Novel oral anticoagulants have emerged from clinical development and are expected to replace older agents with their ease of use and more favorable pharmacodynamic profiles. Hemorrhage is the main concerning adverse event with all anticoagulants. With their ubiquitous use, it becomes important for clinicians to have a sound understanding of anticoagulant pharmacology, dosing and toxicity.

сoagulation, anticoagulants, thrombosis, unfractionated heparin, low molecular weight heparins, direct thrombin inhibitors, warfarin, dabigatran, rivaroxaban, apixaban

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