Aspirin acts by

(A) Cyclo oxygenase pathway # ASPIRIN prduces its antithrombotic effect by irreversibly acetylating and inhibiting platelet cyclo-oxygenase (COX)-1, a critical enzyme in the biosynthesis of thromboxane A2. At high doses, aspirin also inhibits COX-2, an inducible COX isoform found in endothelial cells and inflammatory cells.> Analgesic action of aspirin is mainly due to obstructing of peripheral pain receptors and prevention of prostaglandin mediated sensitization of nerve endings.> Aspirin & some NSAIDs blocked PG generation by inhibiting cyclooxygenase (COX) enzyme.> Aspirin, even in small doses, irreversibly inhibit TXA2 synthesis> Aspirin resets the hypothalamic thermostat & rapidly reduces fever by promoting heat loss but does not decrease heat production