Which drug combination is not rational for acid peptic disease ?

Ans. is 'b' i.e., Rantidine + Sucralfate Sucralfate is an ulcer protective agent. It preferentially and strongly adheres to the ulcer base, especially duodenal, and acts as a physical barrier preventing acid, pepsin and bile from coming in contact with the ulcer base. However, this protective action is attributed to sucralfate because of ceain propeies which are achieved only in acidic medium : Acidic medium gives it a viscous consistency, also polymerizes at pH Vicious and gel like that are responsible for its action. When antacids are given concurrently they raise the pH of gastric secretion and this interferes with the very basic mechanism of action of sucralfate (requires pH).