Proton pump inhibitors (PPIs) are most effective when taken at which time relative to meals?
- A 30–60 minutes before the first meal of the day, as PPIs require active proton pumps (activated by food) for effective binding ✓
- B At bedtime on an empty stomach for maximum overnight acid suppression
- C With meals to ensure absorption is not affected by food
- D Immediately after meals to neutralize post-prandial acid surges
Correct answer: A. 30–60 minutes before the first meal of the day, as PPIs require active proton pumps (activated by food) for effective binding
Explanation
PPIs are prodrugs activated in the acidic canaliculi of parietal cells. They irreversibly inhibit H+/K+-ATPase (proton pump) in its active state. After an overnight fast, up to 70% of proton pumps are quiescent. Eating stimulates proton pump insertion into the canalicular membrane. Taking the PPI 30–60 minutes before a meal ensures maximum pump activation, allowing optimal PPI accumulation and binding. Taking them with meals or at bedtime significantly reduces their efficacy.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
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Written and medically reviewed by the StethoPrep medical team.