How long should I wait to take another medication after taking Prilosec (omeprazole)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: July 9, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Timing Between Prilosec (Omeprazole) and Other Medications

After taking Prilosec (omeprazole), you should wait at least 2 hours before taking most other medications, and at least 4 hours after taking medications that require stomach acid for absorption. 1

How Prilosec Affects Medication Absorption

Omeprazole (Prilosec) is a proton pump inhibitor (PPI) that works by reducing stomach acid production. This reduction in stomach acid can affect how other medications are absorbed in your body:

Mechanism of Action

  • Prilosec begins working within 30-60 minutes of ingestion
  • Peak plasma concentrations occur within 1-3 hours
  • Effects on stomach acid can last up to 72 hours, though the drug is cleared from plasma within 3-4 hours 2

Specific Waiting Times by Medication Type

Medications Requiring Stomach Acid for Absorption

Wait at least 4 hours after taking Prilosec before taking:

  • Antifungals (ketoconazole, itraconazole)
  • Iron supplements
  • Certain antibiotics
  • Thyroid medications

Medications That Bind to Stomach Contents

Wait at least 2 hours before or 4-6 hours after taking:

  • Antacids
  • Sucralfate
  • Bile acid sequestrants 1

Medications With No Significant Interaction

These can generally be taken without special timing considerations:

  • Most antibiotics
  • Pain medications
  • Blood pressure medications
  • Most other medications not listed above

Special Considerations

For Antacids

  • Take at least 2 hours before or 2 hours after Prilosec 1
  • Antacids can reduce the absorption of Prilosec if taken simultaneously

For H2 Blockers (Famotidine, Ranitidine)

  • Avoid taking together with Prilosec as they may interfere with each other's effectiveness 1
  • If both are prescribed, take Prilosec at least 30 minutes before the H2 blocker

For Medications Affected by Cytochrome P450 Enzymes

Prilosec can potentially interact with medications metabolized by the hepatic cytochrome P450 system:

  • Diazepam
  • Phenytoin
  • Warfarin
  • Clopidogrel

Common Pitfalls to Avoid

  1. Taking all medications at the same time as Prilosec - This can reduce the effectiveness of both Prilosec and other medications

  2. Assuming all PPIs have the same interaction profile - Different PPIs may have different interaction profiles

  3. Not informing healthcare providers about Prilosec use - Always tell your doctor and pharmacist about all medications you take, including over-the-counter drugs

  4. Stopping Prilosec abruptly - This can lead to rebound acid hypersecretion

Practical Approach to Medication Timing

  1. Take Prilosec 30-60 minutes before breakfast for optimal effect
  2. Wait at least 2 hours before taking most other medications
  3. For medications requiring stomach acid for absorption, wait at least 4 hours
  4. For antacids, take them at least 2 hours before or after Prilosec
  5. If you're unsure about specific medication interactions, consult your pharmacist or healthcare provider

Following these guidelines will help ensure that both Prilosec and your other medications work as effectively as possible.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Omeprazole: pharmacokinetics and metabolism in man.

Scandinavian journal of gastroenterology. Supplement, 1989

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.