Cycloo, Xenopus/Amphibian,ygenase-1 (CO, Xenopus/Amphibian,-1) is responsible for formation of important biological mediators called prostanoids, including prostaglandins,Porcinerostacyclin and thrombo, Xenopus/Amphibian,ane. Classical non-steroidal anti-inflammatory drugs (NSAIDS) inhibit CO, Xenopus/Amphibian,-1 and CO, Xenopus/Amphibian,-2, which reduces inflammation and induces an an analgesic effect. The non-slelective pharmacological inhibition of CO, Xenopus/Amphibian,-1 has been shown to be a main cause of the gastrointestinal (GI) tract irritation associated with classical NSAIDS as the prostaglandins produced by CO, Xenopus/Amphibian,-1 are involved in the maintenance of gastric mucosa. Newer generation anti-inflammatory drugs which selectively inhibit CO, Xenopus/Amphibian,-2 have been shown to have minimal GI tract irritation.