Treatment for Zollinger-ellison syndrome is: September 2005

Ans. B: Omeprazole Proton pump inhibitors have become the first-line treatment in Zollinger-Ellison syndrome. They are the most effective antisecretory medication available because they block the hydrogen potassium/adenosine triphosphate (ATPase) pump, the final common pathway, regardless of the stimulus. The acid environment in the stomach allows for the release of the prodrug granules, which are then absorbed in the duodenum. Once in the systemic circulation, they are taken up by gastric parietal cells and diffuse into the extracellular canaliculus. The PPI then covalently and irreversibly binds to the proton pump. PPIs require acid for accumulation and activation, which is why they are most efficacious on an empty stomach. PPIs are rapidly and almost completely absorbed. The peak plasma concentration is reached in 1-3 hours. The prodrug is quickly metabolized by the liver, primarily by cytochrome P-450 isoenzyme CYP2C19, resulting in a half-life of roughly 1 hour. Despite the sho half-life of PPIs, the irreversible covalent bonding to the proton pump provides sustained antisecretory effects; therefore, the effect is not due to plasma concentration of the drug but rather the area under the plasma concentration curve.