PPIs & H2 Blockers
The NP-board angle on acid suppressants is recognizing when to deprescribe a PPI rather than start one. Proton pump inhibitors (omeprazole, pantoprazole, esomeprazole) irreversibly block the H+/K+-ATPase and are first-line for GERD, peptic ulcer disease, H. pylori eradication, and stress-ulcer prophylaxis in critical illness. H2 receptor antagonists (famotidine) are second-line and faster-onset but weaker. The board pearls are the long-term harms — C. difficile, community-acquired pneumonia, hypomagnesemia, B12 deficiency, fractures, AKI, and rebound hypersecretion on stop. On the exam, expect a vignette of an elderly patient on a PPI for years with a new fracture, low magnesium, or recurrent C. diff — the answer is taper and stop, not switch to an H2.
📖 Overview
Proton pump inhibitors (omeprazole, pantoprazole) block the final step of gastric acid secretion and are first-line for GERD, peptic ulcer disease, H. pylori eradication (in combo), and stress-ulcer prophylaxis in ICU. H2 blockers (famotidine) are less potent but useful for mild symptoms or as-needed relief. PPIs should be used at the lowest effective dose for the shortest duration.
⚙️ Mechanism of Action
PPIs: irreversible inhibition of H⁺/K⁺-ATPase (proton pump) in gastric parietal cells. H2 blockers: competitive antagonism at histamine H2 receptors on parietal cells.
💎 Board Pearls
- ⏰ PPIs: take 30–60 min BEFORE a meal (needs food to activate proton pumps).
- 🦠 Long-term PPI risks: C. diff infection, CAP, hip fracture, vitamin B12/Mg/Ca deficiency, CKD.
- 💊 Omeprazole + clopidogrel → ↓ clopidogrel activation (CYP2C19); use pantoprazole instead.
- 👵 Famotidine in elderly: renal dose adjust + Beers-listed (confusion risk).
- 🍽️ H. pylori first-line: PPI + amoxicillin + clarithromycin × 14 days (or quadruple therapy).
- ⚠️ PPI abrupt discontinuation after chronic use → acid rebound (taper 2–4 weeks).
- 💡 GERD lifestyle: weight loss, head-of-bed elevation, avoid late meals — often more effective than meds.
- 🧪 Pantoprazole = cleanest drug interaction profile; choose when on multiple meds.
💊 Drugs in This Class
Practice Questions
You are reviewing the chart of a 74-year-old female who has been taking omeprazole (Prilosec) 20 mg daily for 9 years after an episode of reflux in 2017. She has no current GI symptoms and no history of Barrett esophagus, bleeding ulcer, or chronic NSAID use. Which finding is most consistent with a known long-term adverse effect of PPI therapy in this patient?
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