Parecoxib is a prodrug form of the COX-2 inhibitor valdecoxib .1 It is converted to valdecoxib by human liver microsomes in vitro and in vivo in rats, dogs, and cynomolgous monkeys. Parecoxib is also a cannabinoid (CB) receptor 1 agonist with an EC50 value of 2.4 ?M in HEK293 cells.2 It reduces hyperalgesia in a rat model of carrageenan-induced foot pad edema (ED50 = 5 mg/kg) and decreases inflammation in a rat model of M. butyricum-induced arthritis (ED50 = 0.08 mg/kg).1
1.Talley, J.J., Bertenshaw, S.R., Brown, D.L., et al.N-[[(5-methyl-3-phenylisoxazol-4-yl)-phenyl]sulfonyl]propanamide, sodium salt, parecoxib sodium: A potent and selective inhibitor of COX-2 for parenteral administrationJ. Med. Chem.43(9)1661-1663(2000) 2.Schr?der, H., H?llt, V., and Becker, A.Parecoxib and its metabolite valdecoxib directly interact with cannabinoid binding sites in CB1-expressing HEK 293 cells and rat brain tissueNeurochem. Int.58(1)9-13(2011)