Tamsulosin and Warfarin Interaction
Drug interaction information between Tamsulosin and Warfarin.
Tamsulosin and Warfarin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Tamsulosin 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
There is not enough research to know exactly how these drugs interact, but taking them together might change how your blood clots. This could make your treatment less safe.
What To Do
Use caution when taking these drugs together and follow your doctor's advice for monitoring.
FDA Label Information
7.4 Warfarin A definitive drug-drug interaction study between tamsulosin hydrochloride and warfarin was not conducted. Caution should be exercised with concomitant administration of warfarin and tamsulosin hydrochloride capsules [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)].
Tamsulosin Also Interacts With
- Furosemide major
- Paroxetine moderate
- Erythromycin moderate
- Terbinafine moderate
- Dutasteride moderate
Warfarin Also Interacts With
- Fluoxetine major
- Tamoxifen major
- Ibuprofen moderate
- Aspirin moderate
- Diclofenac moderate
Frequently Asked Questions
Can I take Tamsulosin and Warfarin together?
This is a moderate interaction. Use caution when taking these drugs together and follow your doctor's advice for monitoring.
How serious is the interaction between Tamsulosin and Warfarin?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Tamsulosin and Warfarin interact?
There is not enough research to know exactly how these drugs interact, but taking them together might change how your blood clots. This could make your treatment less safe.
Understanding the Tamsulosin and Warfarin Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Tamsulosin belongs to the Alpha-1 Adrenergic 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: There is not enough research to know exactly how these drugs interact, but taking them together might change how your blood clots. 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. Tamsulosin has 18 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: Use caution when taking these drugs together and follow your doctor's advice for monitoring. 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 Tamsulosin 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.