Dutasteride and Tamsulosin Interaction
Drug interaction information between Dutasteride and Tamsulosin.
Dutasteride and Tamsulosin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Dutasteride and Tamsulosin. 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
These drugs are processed by the same system in your liver, which could change the amount of medicine that stays in your blood.
What To Do
Your doctor should use caution and monitor you closely if you are taking both of these medications.
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 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
Can I take Dutasteride and Tamsulosin together?
This is a moderate interaction. Your doctor should use caution and monitor you closely if you are taking both of these medications.
How serious is the interaction between Dutasteride and Tamsulosin?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Dutasteride and Tamsulosin interact?
These drugs are processed by the same system in your liver, which could change the amount of medicine that stays in your blood.
Understanding the Dutasteride and Tamsulosin Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Dutasteride belongs to the 5-Alpha Reductase Inhibitor class and Tamsulosin belongs to the Alpha-1 Adrenergic Blocker class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: These drugs are processed by the same system in your liver, which could change the amount of medicine that stays in your blood. 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. Dutasteride has 16 total documented interactions on file in this dataset, and Tamsulosin has 18. 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: Your doctor should use caution and monitor you closely if you are taking both of these medications. 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 Dutasteride or Tamsulosin 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.