PARECOXIB IS A PRODRUG OF VALDECOXIB. THE MECHANISM OF ACTION OF VALDECOXIB IS BY INHIBITION OF CYCLOOXYGENASE-2 (COX-2)-MEDIATED PROSTAGLANDIN SYNTHESIS. CYCLOOXYGENASE IS RESPONSIBLE FOR
GENERATION OF PROSTAGLANDINS. COX-2 IS THE ISOFORM OF THE ENZYME THAT HAS BEEN SHOWN TO BE INDUCED BY PROINFLAMMATORY STIMULI AND HAS BEEN POSTULATED TO BE PRIMARILY RESPONSIBLE FOR THE SYNTHESIS OF PROSTANOID MEDIATORS OF PAIN,INFLAMMATION, AND FEVER.