Drugs used to affect blood coagulation

Warfarin is active orally. Il is a coumiirin derivative with a siniciure similar 10 that of vitamin K. Warfarin blocks vitamin K-dependent 7-carboxylaiion of glutamate residues (top. shaded). resulting in the production of modified factors VI I. IX. X and prothrombin (U). These arc inactive in promoting coagulation because the y-carbo.xylaiion confers Ca -hinding properties that are essential for the proteins to assemble 

The main side-effect of heparin is bleeding. Because it has a shrrn duration of action (4-6 hours), bleeding can usually be controlled by Slopping the drug administration. If necessary, heparin can be neutralized by the intravenous injection of protamine, a basic jreplide ihai combines with the acidic heparin. Heparin occasionally causes allergic reactions and thrombocytopenia, 

LMW heparins have a longer half-life than standard hepiuin. Htey have the advantages of reiguiring only a single daily dose by subcutaneous injection and prophylactic doses do not require monitoring. 

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