Gastroduodenal mucosal damage with salsalate versus aspirin: results of experimental models and endoscopic studies in humans.

Animal models have identified multiple mechanisms of aspirin toxicity. Aspirin inhibits cyclooxygenase in the gastroduodenal mucosa leading to a decrease in endogenous prostaglandins. Prostaglandin mediated mucus and bicarbonate secretion, epithelial hydrophobicity, blood flow, and cellular proliferation are all decreased. Salicylates may cause direct cellular toxicity via inhibition of energy metabolism and membrane transport properties. Salicylate preparations have been designed to decrease gastroduodenal absorption. Endoscopic studies in humans have confirmed that buffering of aspirin does not ameliorate damage, but enteric coating does. Salicylsalicylic acid (salsalate) is an effective antirheumatic drug that bypasses gastric absorption and also avoids cyclooxygenase inhibition. In a randomized, single-blind, endoscopic comparison of salsalate versus enteric-coated aspirin, significantly less gastroduodenal damage was observed in volunteers after salsalate administration compared to enteric-coated aspirin. An endoscopic study in rheumatoid arthritics also confirmed the ability of salsalate to spare gastroduodenal mucosa when compared to naproxen administration. Salsalate may cause less gastroduodenal damage than enteric-coated aspirin based on the results of animal models and endoscopic studies in humans.