Pharmacological profile of parecoxib: a novel, potent injectable selective cyclooxygenase-2 inhibitor

The antinociceptive, anti-inflammatory, antipyretic effects along with gastric safety profile of parecoxib, a novel, potent selective cyclooxygenase-2 inhibiting prodrug, and those of ketorolac, a nonselective cyclooxygenase inhibitor, were evaluated in various animal models. Parecoxib (up to 20 mg/kg, i.v.) had no effect in two acute pain models, namely, the acetic acid-induced writhing (visceral pain) and the formalin test (tonic pain). However, ketorolac (up to 10 mg/kg, i.v.) showed marked antinociceptive effects in these models. In the models of carrageenan-provoked inflammatory hyperalgesia and inflammation, and in lipopolysaccharide-induced pyrexia, parecoxib significantly reversed all the behavioral changes and it was found to be more potent than ketorolac. Further, ketorolac (10 mg/kg, i.v.) produced visible gastric lesions with prominent petechiae and hemorrhagic streaks. However, parecoxib was without any effect on gastric mucosa. The present results showed that the cyclooxygenase-2 inhibitor, parecoxib, when administered parenterally, has potent antihyperalgesic, anti-inflammatory, antipyretic effects and has a better safety profile than with ketorolac, with sparing of cyclooxygenase-1 in the stomach in these animal models.