Protection by paracetamol against various gastric irritants in the rat.

Four nonsteroid anti-inflammatory drugs (NSAID), indomethacin, phenylbutazone, ibuprofen, and glafenine, caused erosions in the rat stomach in a dose-dependent manner. Paracetamol, which has been shown to protect against the gastric erosive activity of aspirin, reduced the gastric toxicity of indomethacin but was ineffective against the erosive activity of phenylbutazone and glafenine. Only the high erosion score of a large dose of ibuprofen was partly decreased by paracetamol. The gastric damaging effects of necrotizing concentrations of ethanol and sodium hydroxide were strongly reduced by paracetamol, but the erosive activity of hydrochloric acid was only slightly decreased by paracetamol. Thus, although paracetamol protected the gastric mucosa against various noxious agents, this drug was not able to protect against every type of gastric damage. Paracetamol might be protective by stimulating the biosynthesis of prostaglandins in the stomach wall.