Mepirizole, a non-steroidal antiinflammatory compound, its ulcerogenicity and inhibitory action on lesions induced by acidic antiinflammatory agents in the rat stomach.

Gastric lesions were produced in rats by the administration for 2 weeks of 300 mg/kg/day of mepirizole, a basic non-steroidal antiinflammatory compound. Although the single administration of 200 mg/kg of mepirizole had no effect, the addition of water-immersion stress for one hour induced lesions not only in the corpus but also in the pyloric antrum. The administration of 250 mg/kg of mefenamic acid, an acidic non-steroidal antiinflammatory compound (insufficient for producing gastric lesions at this dose alone) with the addition of one hour of water-immersion stress induced gastric lesions. The addition of 200 mg/kg of mepirizole reduced the ulcer index from 8.1 to 4.7 in the corpus and from 4 to 0.5 in the pyloric antrum. It is suggested that basic antiinflammatory compounds inhibit gastric lesions induced by combination of acidic antiinflammatory compounds and water-immersion stress.