Proton Pump Inhibitors (PPIs)

Summary

Proton pump inhibitors or PPIs for short are drugs that inhibit proton or acid production by your stomach. They do this specifically by blocking an ATPase pump that pumps acidic protons out of cells in exchange for bringing potassium into the cell. Reduction of stomach acid is useful in treating acid-mediated disorders like peptic ulcers or acid reflux. Side effects of using PPIs include increased fracture risk as a result of decreased GI calcium absorption, and increased susceptibility to infections. Lastly, PPIs inhibit CYP or cytochrome P450 enzymes, leading to a significant drug interaction risk.

Key Points

• Proton Pump Inhibitors
  • Drug Names (-prazole)
    • Omeprazole, Esomeprazole
    • Lansoprazole, dexlansoprazole
    • Pantoprazole
  • Mechanism
    • Proton Pump Inhibitor (PPI)        
      • Irreversibly inhibit H+/K+ ATPase in stomach parietal cells
        • greatly reduces acid secretion
      • Proton secretion is the final common pathway of gastric acid secretion from parietal cells, which are stimulated by acetylcholine, histamine, and gastrin.
  • Clinical Use
    • Treats Peptic Ulcers
      • Includes Zollinger-Ellison syndrome
      • Component of triple therapy for H pylori
        • 2 antibiotics (amoxicillin, clarithromycin) + PPI
      • Stress ulcer prophylaxis
    • Gastritis
    • GERD (acid reflux)
  • Adverse Effects
    • Increased risk of C difficile infection
    • Pneumonia
    • Acute interstitial nephritis
    • Decreased Ca2+ and Mg2+ absorption
      • Decreased serum Mg2+ with long term use
      • increased fracture risk in elderly
    • P450 inhibitor