Anticoagulants prevent clotting (coagulation) of blood. They prevent formation of clots or

break up clots in blood vessels in conditions such as thrombosis and embolism. They also

are used to prevent coagulation in preserved blood used for transfusions. Heparin is a

natural anticoagulant purified from pig intestine or bovine (cow) lung. It is found in the

granules of certain white blood cells. A more easily administered form of heparin called

low-molecular-weight heparin (Fragmin, Lovenox) is self-injected on a daily basis and

requires no monitoring of blood clotting ability, as is done with regular heparin. Other

anticoagulants, including warfarin (Coumadin), are chemically synthesized. Coumadin

blocks the formation of a number of clot-forming factors in the blood. Its action is reversed

by vitamin K. Tissue-type plasminogen activator (tPA) dissolves clots and is used to open

vessels after myocardial infarction.

New anticoagulant drugs that greatly reduce the risk of stroke are called NOACs (new

oral anticoagulants). Examples are apixaban (Eliquis), dabigatran (Pradaxa), and rivaroxaban


Antiplatelet drugs reduce the tendency of platelets to stick together. Aspirin is an

example of an antiplatelet drug; daily aspirin prophylaxis is recommended for patients with

coronary artery disease and for those who have had heart attacks. Clopidogrel (Plavix)

inhibits clumping of platelets and is used to prevent clotting after heart attacks and blood

vessel procedures, such as angioplasty.

Anticoagulants and antiplatelet drugs are listed such as apixaban (Eliquis), clopidogrel (Plavix), and rivaroxaban (Xarelto), etc..