Omeprazole
Brand names: Prilosec
Class: 🔥 PPIs & H2 Blockers
On board day, omeprazole is the prototypical proton pump inhibitor — and the prototypical drug to deprescribe. It irreversibly blocks the parietal cell H+/K+-ATPase and is first-line for GERD, peptic ulcer disease, H. pylori eradication (with antibiotics), Zollinger-Ellison syndrome, and stress-ulcer prophylaxis in critical illness. Take 30 minutes before the first meal of the day. Long-term harms are the high-yield content for the AANP exam: C. difficile infection, community-acquired pneumonia, hypomagnesemia, B12 deficiency, fragility fractures, AKI, and rebound hypersecretion when stopped abruptly. Omeprazole inhibits CYP2C19 and reduces clopidogrel activation — pantoprazole is the cleaner PPI in stented patients.
✅ Indications
GERD, PUD, H. pylori (combo), Zollinger-Ellison, stress ulcer prophylaxis.
⚙️ Mechanism of Action
Proton pump inhibitor — irreversibly blocks H⁺/K⁺-ATPase.
📏 Dosing
20–40 mg PO daily, 30–60 min BEFORE meals.
🚫 Contraindications
Hypersensitivity.
⚠️ Adverse Effects
Long-term: C. diff, CAP, hip fracture, B12/Mg/Ca deficiency, CKD, rebound acid hypersecretion on discontinuation.
🔬 Monitoring
Magnesium after 1 year, B12 periodically with chronic use; bone density if other risk factors.
💎 Board Pearls
- ⏰ 30–60 MIN BEFORE meals — needs to reach parietal cells while proton pumps are active.
- 🚫 OMEPRAZOLE + CLOPIDOGREL → ↓ clopidogrel effect (CYP2C19 inhibition) → SWITCH TO PANTOPRAZOLE.
- 🦠 Long-term risks: C. diff, pneumonia, B12 deficiency, fractures, CKD, hypomagnesemia.
- ⚠️ Taper off chronic PPI (rebound acid hypersecretion); step down to H2 blocker.
Practice Questions
When educating a patient about omeprazole (Prilosec) therapy, what is the correct timing instruction?
Related Drugs in This Class
- Pantoprazole — Protonix
- Famotidine — Pepcid
Sources
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