Anti-thrombotic drugs

These are platelet aggregation inhibitors (through a decreased formation or effect of chemical signals).
Mechanism of action:
In a series of reactions, when a vessel is injured, finally activation of membrane glycoprotein (GP) receptors takes place leading to binding of several adhesive proteins i.e. von Willebrand factor, fibronectin and fibrinogen.

Most important of GP-receptors is GP IIb/IIIa receptors upon which binding of fibrinogen takes place, through platelet activators like TXA2, ADP or thrombin, on two separate platelets resulting in the platelet cross linking and platelet aggregation leading to thrombus formation.

These drugs either cause inhibition of cyclo-oxygenase-1 (COX-1) or block GP IIb/IIIa receptors.