Though these PPIs share the core structures benzimidazole and pyridine, their pharmacokinetics and pharmacodynamics are a little different. Omeprazole was the first PPI introduced in market, followed by pantoprazole, lansoprazole and rabeprazole.
Cys813 is the primary site responsible for the inhibition of acid pump enzyme, where PPIs bind. Activated PPI binds covalently to the gastric H +, K +-ATPase via disulfide bond.
Proton pump inhibitor (PPI) is a prodrug which is activated by acid.