Anti-platelet agents...to be expanded further.

Antiplatelet drugs alter the platelet activation at the site of vascular damage crucial to the development of arterial thrombosis.

Aspirin
irreversibly inhibits the enzyme COX, resulting in reduced platelet production of TXA2 (thromboxane - powerful vasoconstrictor which lowers cyclic AMP and initiates the platelet release reaction).

Dipyridamole
inhibits platelet phosphodiesterase, causing an increase in cyclic AMP with potentiation of the action of PGI2 – opposes actions of TXA2

Clopidogrel
affects the ADP-dependent activation of IIb/IIIa complex

Glycoprotein IIb/IIIa receptor antagonists block a receptor on the platelet for fibrinogen and von Willebrand factor. 3 classes:
Murine-human chimeric antibodies (e.g. abciximab)
Synthetic peptides (e.g. eptifibatide)
Synthetic non-peptides (e.g. tirofiban)