Prevention of peptic ulcer relapse by sucralfate: mechanisms of action.

Sucralfate has a complex effect on the luminal and mucosal environment of the stomach and duodenum. Some of the actions are important in ulcer healing whilst others are important in preventing subsequent ulcer relapse. Although sucralfate has little direct effect on acid secretion, there is evidence that after ulcer healing with this drug, parietal cell responsiveness is reduced. This may in part be mediated by increased somatostatin release from gastric D cells and may be important in reducing ulcer relapse. Sucralfate has been shown to increase mucosal resistance to damaging agents, such as ethanol and aspirin. Studies have shown that this protective action may be related to the drugs effect on various protective zones such as the 'mucous-bicarbonate' barrier, mucosal hydrophobicity, epithelial cell function and morphology, and mucosal blood flow. These complex actions of sucralfate are in part related to direct interaction between the drug or its components and gastroduodenal tissues, and in part related to effects on various mediators of tissue injury and repair.