What are COX inhibitors (Aspirin)?

Aspirin inhibits thromboxane A2 synthesis from arachidonic acid in platelets by irreversible acetylation of a serine residue on the active site of COX-1, thereby irreversibly inactivating the enzyme. The inhibitory effect is rapid and the resulting suppression of platelet aggregation last for the life of the platelet, which is approximately 7 to 10 days. Aspirin is the only antiplatelet agent that irreversibly inhibits platelet function.