Tamsulosin and Terbinafine Interaction
Drug interaction information between Tamsulosin and Terbinafine.
Tamsulosin and Terbinafine have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Tamsulosin and Terbinafine. 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
Terbinafine slows down the body's ability to break down tamsulosin by blocking a specific liver enzyme. This can lead to higher levels of tamsulosin in your blood.
FDA Label Information
Tamsulosin hydrochloride capsules should be used with caution in combination with moderate inhibitors of CYP3A4 (e.g., erythromycin), in combination with strong (e.g., paroxetine) or moderate (e.g., terbinafine) inhibitors of CYP2D6, or in patients known to be CYP2D6 poor metabolizers, particularly at a dose higher than 0.4 mg (e.g., 0.8 mg). The effects of concomitant administration of a moderate CYP2D6 inhibitor (e.g., terbinafine) on the pharmacokinetics of tamsulosin hydrochloride have not been evaluated [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)].
Tamsulosin Also Interacts With
- Furosemide major
- Paroxetine moderate
- Warfarin moderate
- Erythromycin moderate
- Dutasteride moderate
Terbinafine Also Interacts With
- Ketoconazole minor
- Fluconazole minor
- Cyclosporine minor
- Trimethoprim minor
- Rifampin minor
Frequently Asked Questions
What SPL severity band is on file for Tamsulosin + Terbinafine?
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?
Tamsulosin has 18 labeled pairs on file vs Terbinafine's 17. In the moderate band specifically: Tamsulosin has 8 (also Paroxetine, Warfarin, Erythromycin, Dutasteride); Terbinafine has 1.
What mechanism field is on file for Tamsulosin and Terbinafine?
Terbinafine slows down the body's ability to break down tamsulosin by blocking a specific liver enzyme. This can lead to higher levels of tamsulosin in your blood.
Tamsulosin carries more major-labeled pairs than Terbinafine
SPL source-record counts only. This page's band is moderate · classes on file: Tamsulosin (Alpha-1 Adrenergic Blocker); Terbinafine (Allylamine Antifungal).
Tamsulosin has 1 major-labeled pair vs Terbinafine's 0. 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
- Warfarin
- Erythromycin
- Dutasteride
0 major · 1 moderate · 16 minor · 17 total
Terbinafine has no other moderate-band peer in this dataset besides Tamsulosin.
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.