Propranolol and Warfarin Interaction
Drug interaction information between Propranolol and Warfarin.
Propranolol and Warfarin have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Propranolol 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
Propranolol increases the amount of warfarin in your blood. This makes the blood thinner and increases your risk of bleeding.
What To Do
Your doctor may need to change your warfarin dose. You will need more frequent blood tests to check your clotting levels.
FDA Label Information
Warfarin Propranolol when administered with warfarin increases the concentration of warfarin.
Propranolol Also Interacts With
- Clonidine minor
- Diltiazem minor
- Verapamil minor
- Doxazosin minor
- Haloperidol minor
Warfarin Also Interacts With
- Fluoxetine major
- Tamoxifen major
- Ibuprofen moderate
- Aspirin moderate
- Diclofenac moderate
Frequently Asked Questions
Can I take Propranolol and Warfarin together?
This is a minor interaction. Your doctor may need to change your warfarin dose. You will need more frequent blood tests to check your clotting levels.
How serious is the interaction between Propranolol 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 Propranolol and Warfarin interact?
Propranolol increases the amount of warfarin in your blood. This makes the blood thinner and increases your risk of bleeding.
Understanding the Propranolol and Warfarin Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Propranolol belongs to the Non-Selective Beta-Blocker 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: Propranolol increases the amount of warfarin in your blood. 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. Propranolol has 44 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 may need to change 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 Propranolol 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.