In the treatment of ulcers, sucralfate is helpful in protecting the surface of the ulcer. In the acidic environment of the stomach (pH < 4), it reacts with hydrochloric acid to form a cross-link with tissue proteins at the surface of ulcers and other lesions. This complex protects the tissue from further damage by acid and pepsin. In this role, the mechanism of action of sucralfate is similar to that of bismuth.
Sulcralfate also has an indirect role in decreasing acid production. It has been shown to stimulate prostaglandin E2 production. Prostaglandin E2 inhibits the acid production by the parietal cell.
Side effects include constipation, nausea, allergic skin reactions, and bezoar (a mass found trapped in the GI system).