Actions of antiulcer medications

H2 receptor antagonists inhibit acid secretion by blocking histamine H2 receptors on the parietal cell. The proton pump inhibitors (PPIs; eg, omeprazole, lansoprazole, pantoprazole, esomeprazole, and rabeprazole) effectively block acid secretion by irreversibly binding to and inhibiting the hydrogen-potassium ATPase pump that resides on the luminal surface of the parietal cell membrane. The mechanism involved in antacid healing of peptic ulcers may include neutralizing gastric acid, but probably also includes a number of other factors.