Furosemide and Tamsulosin Interaction
Drug interaction information between Furosemide and Tamsulosin.
Furosemide and Tamsulosin have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Furosemide and Tamsulosin. 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
Furosemide slightly lowers the level of tamsulosin in your system, but the effect is too small to change how the medicine works.
FDA Label Information
7.7 Furosemide Tamsulosin hydrochloride capsules had no effect on the pharmacodynamics (excretion of electrolytes) of furosemide. While furosemide produced an 11% to 12% reduction in tamsulosin hydrochloride C max and AUC, these changes are expected to be clinically insignificant and do not require adjustment of the tamsulosin hydrochloride capsules dosage [see Clinical Pharmacology (12.3)].
Furosemide Also Interacts With
- Dutasteride major
- Dutasteride/Tamsulosin major
- Cyclosporine moderate
- Lithium moderate
- Oxaprozin moderate
Tamsulosin Also Interacts With
- Paroxetine moderate
- Warfarin moderate
- Erythromycin moderate
- Terbinafine moderate
- Dutasteride moderate
Frequently Asked Questions
What SPL severity band is on file for Furosemide + Tamsulosin?
Compiled FDA labeling labels this pair major. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Furosemide has 36 labeled pairs on file vs Tamsulosin's 18. In the major band specifically: Furosemide has 3 (also Dutasteride, Dutasteride/Tamsulosin); Tamsulosin has 1.
What mechanism field is on file for Furosemide and Tamsulosin?
Furosemide slightly lowers the level of tamsulosin in your system, but the effect is too small to change how the medicine works.
Furosemide carries more major-labeled pairs than Tamsulosin
SPL source-record counts only. This page's band is major · classes on file: Furosemide (Loop Diuretic); Tamsulosin (Alpha-1 Adrenergic Blocker).
Furosemide has 3 major-labeled pairs vs Tamsulosin's 1.
3 major · 4 moderate · 29 minor · 36 total
- Other major peers for Furosemide
- Dutasteride
- Dutasteride/Tamsulosin
1 major · 8 moderate · 9 minor · 18 total
Tamsulosin has no other major-band peer in this dataset besides Furosemide.
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.