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. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
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.
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
What SPL severity band is on file for Tamsulosin + Warfarin?
Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Warfarin has 163 labeled pairs on file vs Tamsulosin's 18. In the moderate band specifically: Tamsulosin has 8 (also Paroxetine, Erythromycin, Terbinafine, Dutasteride); Warfarin has 28 (also Ibuprofen, Aspirin, Diclofenac, Desvenlafaxine).
What mechanism field is on file for Tamsulosin and Warfarin?
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.
Warfarin carries more major-labeled pairs than Tamsulosin
SPL source-record counts only. This page's band is moderate · classes on file: Tamsulosin (Alpha-1 Adrenergic Blocker); Warfarin (Vitamin K Antagonist (Anticoagulant)).
Warfarin has 2 major-labeled pairs vs Tamsulosin's 1. This page itself is in the moderate band, not the major band.
1 major · 8 moderate · 9 minor · 18 total
- Other moderate peers for Tamsulosin
- Paroxetine
- Erythromycin
- Terbinafine
- Dutasteride
2 major · 28 moderate · 133 minor · 163 total
- Other moderate peers for Warfarin
- Ibuprofen
- Aspirin
- Diclofenac
- Desvenlafaxine
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.