Nursing Pharmacology  Chapter 12:  Anxiolytics and Sedative-Hypnotics

• Proton pump inhibitors:

  • Overview:

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

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

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

  • Specific drugs:

    • Omeprazole (Prilosec)

      • Dosage (adult):

        • Intravenous dosage is 40 mg administered 30 minutes prior to induction

        • The oral dose range is between 40 and 80 mg administered between 2 and 4 hours before the procedure

      • Mechanism of action: Omeprazole (Prilosec) and lansoprazole (Prevacid) bind "irreversibly" to the proton pump. 

        • This action result in an extended duration of action, since new protein must be synthesized to reestablish proton secretion function.

      • Duration of action: The effect on gastric pH may be as long as 24 hours with variable effects on gastric volume (omeprazole (Prilosec)).