Sucrafate a substituted sugar molecule with no nutritional value, does not inhibit gastric acid, but rather , reacts with existing stomach acid to from a thick coating that covers the surface of an ulcer, protecting the open area from further damage. A secondary effect is to act as an inhibitor of the digestive enzyme pepsin. Sucralfate does not bind to the normal stomach lining. The drug has been used for prevention of stress ulcers, the type seen in patients exposed to physical stress such as burn and surgery It has no systemic effects.