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Dutasteride and Warfarin Interaction

Drug interaction information between Dutasteride and Warfarin.

Dutasteride and Warfarin have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Dutasteride and Warfarin. 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.

Drug A

Dutasteride

5-Alpha Reductase Inhibitor

Drug B

Warfarin

Vitamin K Antagonist (Anticoagulant)

How They Interact

There is not enough research to know exactly how these drugs interact, but they might change how your blood-thinning medicine works.

What To Do

Use caution when taking these together and follow your doctor's advice for any extra blood tests.

FDA Label Information

7.2 Warfarin Dutasteride Concomitant administration of dutasteride 0.5 mg/day for 3 weeks with warfarin does not alter the steady-state pharmacokinetics of the S- or R-warfarin isomers or alter the effect of warfarin on prothrombin time [see Clinical Pharmacology ( 12.3 ) ] . Tamsulosin A definitive drug-drug interaction trial between tamsulosin hydrochloride and warfarin was not conducted. Caution should be exercised with concomitant administration of warfarin and tamsulosin-containing products, including dutasteride and tamsulosin hydrochloride capsules [see Warnings and Precautions (...

Warfarin Also Interacts With

View all Warfarin interactions →

Frequently Asked Questions

Can I take Dutasteride and Warfarin together?

This is a moderate interaction. Use caution when taking these together and follow your doctor's advice for any extra blood tests.

How serious is the interaction between Dutasteride and Warfarin?

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 Warfarin interact?

There is not enough research to know exactly how these drugs interact, but they might change how your blood-thinning medicine works.

Understanding the Dutasteride and Warfarin 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 Warfarin belongs to the Vitamin K Antagonist (Anticoagulant) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: There is not enough research to know exactly how these drugs interact, but they might change how your blood-thinning medicine works. 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 Warfarin has 163. 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: Use caution when taking these together and follow your doctor's advice for any extra blood tests. 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 Warfarin 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.