ABSTRACT
Anticoagulant drugs are used to prevent and treat venous thrombo-embolism. Antiplatelet agents are mostly used to inhibit arterial thrombosis, but have a place in managing venous thrombosis. Thrombolytic agents are used to enhance intrinsic fibrinolysis to treat established thrombosis and embolism. Anti-platelet agents are mostly used to inhibit arterial thrombosis but can be used to inhibit venous thrombosis. Unfractionated heparin (UFH) acts immediately after intravenous injection and within 20–30 minutes after subcutaneous injection of its slowly- absorbed calcium salt calciparine. UFH readily binds to plasma proteins which contribute to its variable anticoagulant response after parenteral administration. UFH is modified by isolating fragments of molecular weight less than 9000 daltons to form low molecular weight heparin, and this has made its pharmacodynamics more predictable. Fondaparinux sodium is a synthetic analogue of the pentasaccharide sequence in the heparins that mediates their interaction with antithrombin.
