heparin

heparin One of several glycosaminoglycans (GAGs), an anticlotting agent produced naturally by the liver and some other cells in the body. Heparin may also be purified or synthesized for use as a medication. As a drug, heparin is useful in preventing blood clots that travel from their site of origin through the bloodstream to clog another vessel (thromboembolic complications); it is used also in the early treatment of blood clots in the lungs (pulmonary embolisms) and clotting-related heart conditions. See also glycosaminoglycan; heparin, low-weight.