Proton Pump Inhibitors

• Parietal cells H ion secretion depends on a H+,K+-ATPase pump-- promoting H K exchange

• H⁺,K⁺-ATPase located in apical membrane to and tubulovesicular apparatus of parietal cells

• Luminal surface of the membrane enzyme: exposed to gastric luminal acid

• Omeprazole and lansoprazole inhibit the proton pump, effectively irreversibly -- requiring synthesis of new enzyme protein

• Omeprazole and lansoprazole approved for treatment of:

  • duodenal ulcer

    •   may be used in conjunction with triple therapy

  • erosive esophagitis

  • gastric acid hypersecretory states, including Zollinger-Ellison syndrome

Friedman, L. S. and Peterson, W.L. Peptic Ulcer and Related Disorders In Harrison's Principles of Internal Medicine 14th edition, (Isselbacher, K.J., and Braunwald, E., Wilson, J.D., Martin, J.B., Fauci, A.S. and Kasper, D.L., eds) McGraw-Hill, Inc (Health Professions Division), 1998, pp. 1597-1616.