An antithrombotic agent is a drug that reduces the formation of blood clots (thrombi). Antithrombotics can be used therapeutically for prevention (primary prevention, secondary prevention) or treatment of a dangerous blood clot (acute thrombus). In the U.S., the American College of Chest Physicians publishes clinical guidelines for clinicians for the use of these drugs to treat and prevent a variety of diseases.
Different antithrombotics affect different blood clotting processes: