Proton Pump Inhibitor Therapy

Proton pump inhibitor therapy causes a profound and prolonged reduction in stomach acid production by irreversibly blocking the hydrogen-potassium ATPase enzyme in the acid-producing cells of the stomach lining. Taken orally, proton pump inhibitors are absorbed in the small intestine and travel through the bloodstream to these cells, where they become activated in the highly acidic environment inside the cell and bind permanently to the proton pump, reducing gastric acid secretion by up to 99 percent, a substantially larger effect than the older H2-receptor antagonist drugs; because the inhibition is irreversible, acid production only recovers as the cell manufactures new proton pumps through ordinary turnover. The drugs treat dyspepsia, peptic ulcers, gastroesophageal reflux disease, Barrett esophagus and eosinophilic esophagitis, are used as part of therapy to eradicate Helicobacter pylori infection, and help prevent stress ulcers in critically ill patients.