Treatment / Reduce acidity / PPIs
Proton pump inhibitors
ESOMEPRAZOLE/OMEPRAZOLE, LANSOPRAZOLE, PANTOPRAZOLE, RABEPRAZOLE
 |
Proton pump inhibitors are the most effective agents for reducing intragastric acidity because they IRREVERSIBLY block the final common pathway in acid secretion --- H+/K+ ATPase. |
- in 2013, PPIs were among the top drugs (by retail sales):
- ESOMEPRAZOLE (Nexium) #2
- OMEPRAZOLE (Prilosec; various generics)#100
- LANSOPRAZOLE (Prevacid)
- PANTOPRAZOLE (Protonix)
- RABEPRAZOLE (Aciphex) #81
- From a pharmacology perspective, PPIs are ideal drugs! They have a short serum half-life but long duration of action, and they selectively inhibit a protein with restricted distribution, which limits side effects.
Mechanism of action
- irreversible inhibitors of ACTIVE H+/K+ ATPase for 48+ hours
- H+/K+ ATPase is only found in the parietal cell --> minimal side effects
- particularly useful in the treatment of Zollinger-Ellison syndrome and GERD (conditions where H2 blockers are not completely satisfactory)
One final note: PPIs have only modest efficacy in treating non-ulcer-related dyspepsia (10-20% compared to placebo). Despite marketing claims to the contrary, PPIs have not been conclusively shown to be superior to either H2 antagonists or antacids in providing symptomatic relief for heartburn.