Question
Lansoprazole
Answer
Lansoprazole is a proton pump inhibitor (PPI).
MOA: lansoprazole (a prodrug) → accumulates in the acidic parietal cell canaliculus → converted to its active sulfenamide form → irreversibly binds H⁺/K⁺-ATPase (the proton pump) → blocks the final common step of acid secretion regardless of the stimulating pathway (histamine, gastrin, or acetylcholine), giving PPIs the most potent acid suppression of any class.
Uses: peptic ulcer disease, GERD, H. pylori eradication (as part of triple therapy), Zollinger-Ellison syndrome, prevention of NSAID-induced ulcers.
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 (all traceable to chronic acid suppression removing acid’s normal physiological functions).