What is the difference between the mechanisms of action of heparin and warfarin in treating thrombosis?

Answer 1

Heparin is an indirect antithrombotic agent. When antithrombin III binds to thrombin, the thrombin gets broken down. However, this binding reaction happens at a very slow rate. Heparin can sped up this reaction by inducing a confrontational change in antithrombin III.

Warfarin is a vitamin K epoxide reductase inhibitor. It prevents vitamin K from being reduced. Vitamin K is an essential cofactor for gamma-glutamyl carboxylase. This enzyme turns the Glu of Factor X into Gla. The calcium ions can only bind to Gla to enable Factor X to undergo a confrontational change so that it can itneract with the tissue factor and the VIIa cofactor.

Answer 2

Dipyridamol inhibits PDE and nucleoside transporters. This enhances the activity of cAMP . This results in the intracellular calcium being decrease and GPIIb/IIIa being blocked and platelet aggregation can hence be inhibited.

Clopidogrel acts on the ADP receptors. It prevents P2Y12 from being formed and hence also prevents GPIIb/IIIa from being formed. It can therefore reduce platelet aggregation.