HEPARIN
It is a powerful and instantaneously acting anticoagulant, effective both in vivo & in vitro. It acts indirectly by activating plasma anti thrombin III (At III, an alpha globulin) and may be other similar cofactors. The complex then binds to clotting factor Xa, IIa, IXa, XIIa and XIIIa and inactivates them. At low conc. of heparin, factor Xa mediated conversion of prothrombin to thrombin is selectively affected. Thrombin (IIa) mediated conversion of fibrinogen to fibrin is also quite sensitive.Thrombo-embolic conditions. Prophylaxis of deep vein thrombosis in major surgery. Lipemia clearing.
5,000-10,000 U. every 4-6 hrs or deep S.C. injection of 25,000 U. every 12-24 hrs. Children : 50-100 U./kg every 4-6 hrs.
Bleeding disorders, throm- bocytopenia, severe hypertension, threatened abortion, piles, G.I. ulcers. Subacute bacterial endocarditis, large malignancies, tuberculosis. Ocular and neurosurgery, lumbar puncture. Chronic alcoholics, Aspirin & other antiplatelet drugs.
Renal or hepatic impairment. Paediatrics: Reduce dose accodring to age and wt. Pregnancy: Use if clearly indicated, may cause excessive bleeding if taken near delivery. Lactation: No evidence of risk. Elderly: No special problem.
Bleeding due to overdose. Transient & reversible alopecia. Osteoporosis.Hypersensitivity.
Salicylates and dipyridamole enhance activity, effect increase by oral anticoagulants, phenylbutazone, streptokinase and in combination with dihydroergotamine mesylate.
