Despite their sho half lives(2hrs) proton pump inhibitors cause a prolonged suppresion of acid secretiin(upto 48hr) because:
They irreversibly inhibit the proton pump molecule and hence,acid secretion requires synthesis of new proton pumps(ref Rang and Dale 5/e p370-371, goidman gilman 12/e p1311-1312) The activated form of PPI binds covalently with sulfahydryl groups of cysteine in the H+ K+ atpase ,irreversbly inacativating the pump molecule.acid secretion resumes only after new pump molecules are synthesized and inseed into the luminal membranes ptoviding a prolonged suppresion of acid secretion despite the much shoer pladma half lives of the parent compounds.
They are prodrugs and undergo activation gradually
They exit from the palsma and enter acid secretory canaliculi and stay there blocking the secretion of acid for a long time
They irreversibly inhibit the proton pump molecule and hence,acid secretion requires synthesis of new proton pumps
They are available as enteric coated capsules,from which drug is gradually released
Gastrointestinal tract