Dutasteride/Tamsulosin and Tamsulosin Interaction
Drug interaction information between Dutasteride/Tamsulosin and Tamsulosin.
Dutasteride/Tamsulosin and Tamsulosin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Dutasteride/Tamsulosin 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
Taking both of these means you are taking the same medicine twice, which can cause your blood pressure to drop too low or cause other side effects.
FDA Label Information
7 DRUG INTERACTIONS There have been no drug interaction trials using dutasteride and tamsulosin hydrochloride capsules. Because of the potential for drug-drug interactions, use caution when prescribing a dutasteride-containing product, including dutasteride and tamsulosin hydrochloride capsules, to patients taking potent, chronic CYP3A4 enzyme inhibitors (e.g., ritonavir) [see Clinical Pharmacology ( 12.3 ) ] . Tamsulosin Strong and Moderate Inhibitors of CYP3A4 or CYP2D6: Tamsulosin is extensively metabolized, mainly by CYP3A4 or CYP2D6.
Dutasteride/Tamsulosin Also Interacts With
- Furosemide major
- Warfarin moderate
- Paroxetine minor
- Atenolol minor
- Diltiazem minor
Tamsulosin Also Interacts With
- Furosemide major
- Paroxetine moderate
- Warfarin moderate
- Erythromycin moderate
- Terbinafine moderate
Frequently Asked Questions
What SPL severity band is on file for Dutasteride/Tamsulosin + Tamsulosin?
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 Dutasteride/Tamsulosin's 15. In the moderate band specifically: Dutasteride/Tamsulosin has 2 (also Warfarin); Tamsulosin has 8 (also Paroxetine, Warfarin, Erythromycin, Terbinafine).
What mechanism field is on file for Dutasteride/Tamsulosin and Tamsulosin?
Taking both of these means you are taking the same medicine twice, which can cause your blood pressure to drop too low or cause other side effects.
Tamsulosin's labeled portfolio outnumbers Dutasteride/Tamsulosin
SPL source-record counts only. This page's band is moderate · classes on file: Dutasteride/Tamsulosin (5-ARI / Alpha-Blocker Combination); Tamsulosin (Alpha-1 Adrenergic Blocker).
1 major · 2 moderate · 12 minor · 15 total
- Other moderate peers for Dutasteride/Tamsulosin
- Warfarin
1 major · 8 moderate · 9 minor · 18 total
- Other moderate peers for Tamsulosin
- Paroxetine
- Warfarin
- Erythromycin
- Terbinafine
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.