About Pantoprazole A proton pump inhibitor, Benzimidazole derivative, Anti ulcer. Mechanism of Action of Pantoprazole Pantoprazole is a proton pump inhibitor. It is a prodrug. After administration it diffuses in to the parietal cell of the stomach and accumulates in the secretory canaliculi. In the acidic medium Pantoprazole is converted to sulfenamide. This sulfenamide covalently interacts with sulfhydryl (SH) group in the proton pump (H+ K+ATPase) and inhibits the exchange of extracellular K+ for intracellular H+ ion. Pantoprazole irreversibly inhibits proton pumps activity and decreases gastric acid secretion. Pantoprazole is more acid stable and its activity is lowered in higher pH. It is the only proton pump inhibitor which is available as parenteral form.