Maximum Daily Dose of Omeprazole
The maximum daily dose of omeprazole is 80 mg per day in adults, though standard therapeutic dosing rarely exceeds 40 mg daily for most indications. 1, 2
Standard Maximum Dosing
- For most acid-related conditions in adults, the maximum recommended dose is 40 mg daily, which can be given as a single dose or divided into 20 mg twice daily 3, 1
- When co-administered with glecaprevir/pibrentasvir for hepatitis C treatment, do not exceed 40 mg daily, as higher doses have not been studied and may reduce antiviral drug concentrations 1
Higher Dosing for Specific Conditions
- For chronic cough due to GERD, omeprazole 40 mg twice daily (total 80 mg/day) has been used for 8-12 weeks in clinical studies 3, 1
- In Zollinger-Ellison syndrome, doses ranging from 20 to 360 mg daily (median 60-70 mg) have been successfully used, with the recommended starting dose being 60 mg/day 2, 4
- For refractory GERD cases, omeprazole 40 mg twice daily for at least 12 weeks has been studied 3
Pediatric Maximum Dosing
- For children with eosinophilic esophagitis, the maximum dose is 1 mg/kg twice daily, not to exceed 40 mg twice daily (total 80 mg/day) 5, 6
- For standard pediatric GERD in children ≥20 kg, the maximum dose is 20 mg once daily 5
- In severe or refractory pediatric GERD, doses may be escalated up to 1.4-2.8 mg/kg/day in divided doses 5
Clinical Context
- The FDA label indicates that omeprazole 20 mg and 40 mg doses produce dose-related inhibition of acid secretion, with 40 mg producing approximately 94% decrease in basal acid output versus 78% with 20 mg 7
- The antisecretory effect reaches a plateau after 4 days of once-daily dosing, and the effect lasts up to 72 hours after a single dose due to irreversible binding to the proton pump 7, 8
- Historical research demonstrates that doses up to 360 mg daily have been used safely in Zollinger-Ellison syndrome for up to 4 years, though such extreme dosing is reserved for pathological hypersecretory conditions 9, 2
Important Caveats
- Doses exceeding 40 mg daily should only be used for specific indications such as pathological hypersecretory conditions, refractory GERD, or eosinophilic esophagitis 1, 2
- Weight-based pediatric dosing should NOT be extrapolated to premature infants due to immature renal function and risk of drug accumulation 5
- For maintenance therapy in most conditions, attempt to reduce to the lowest effective dose (typically 20 mg daily) after initial treatment 2, 10