Lansoprazole and Warfarin Interaction
Drug interaction information between Lansoprazole and Warfarin.
Lansoprazole and Warfarin have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Lansoprazole and Warfarin. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Lansoprazole can change how your body handles warfarin, which can make your blood thinner than it should be.
What To Do
Your doctor should check your blood clotting levels more often and may need to adjust your warfarin dose.
FDA Label Information
Warfarin Clinical Impact: Increased INR and prothrombin time in patients receiving PPIs and warfarin concomitantly. Dose adjustment of warfarin may be needed to maintain target INR range. See prescribing information for warfarin.
Lansoprazole Also Interacts With
- Amoxicillin major
- Clarithromycin major
- Rifampin moderate
- Tacrolimus Topical moderate
- Methotrexate minor
Warfarin Also Interacts With
- Fluoxetine major
- Tamoxifen major
- Ibuprofen moderate
- Aspirin moderate
- Diclofenac moderate
Frequently Asked Questions
Can I take Lansoprazole and Warfarin together?
This is a minor interaction. Your doctor should check your blood clotting levels more often and may need to adjust your warfarin dose.
How serious is the interaction between Lansoprazole and Warfarin?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Lansoprazole and Warfarin interact?
Lansoprazole can change how your body handles warfarin, which can make your blood thinner than it should be.
Understanding the Lansoprazole and Warfarin Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Lansoprazole belongs to the Proton Pump Inhibitor (PPI) class and Warfarin belongs to the Vitamin K Antagonist (Anticoagulant) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Lansoprazole can change how your body handles warfarin, which can make your blood thinner than it should be. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Lansoprazole has 14 total documented interactions on file in this dataset, and Warfarin has 163. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your doctor should check your blood clotting levels more often and may need to adjust your warfarin dose. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Lansoprazole or Warfarin based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.