Paper II
Question
Omeprazole
Answer
Omeprazole is a proton pump inhibitor.
MOA: a prodrug that accumulates in the acidic parietal cell canaliculus, converts to its active sulfenamide form, and irreversibly binds H⁺/K⁺-ATPase, blocking the final common step of gastric acid secretion regardless of the stimulating pathway.
Uses: peptic ulcer disease, GERD, H. pylori eradication (triple therapy), Zollinger-Ellison syndrome.
Adverse effects: generally well tolerated short-term; long-term use — hypomagnesemia, increased fracture risk, vitamin B12 deficiency, increased susceptibility to enteric infections including C. difficile.

