Dutasteride and Fluconazole: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Fluconazole
Dutasteride
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased dutasteride exposure and risk for toxicity
Interaction Deep Dive
Concomitant use of a CYP3A4 substrate, such as dutasteride, with fluconazole (a moderate CYP3A4 inhibitor) may increase exposure to dutasteride and increase the risk for toxicity. Caution and careful monitoring is advised when using this type of combination of drugs. Fluconazole-mediated enzyme inhibition may persist for 4 to 5 days after discontinuation1
Why it happens (mechanism)
Inhibition of CYP3A4-mediated dutasteride metabolism by fluconazole
Common questions
Can I take Dutasteride and Fluconazole together?
Increased dutasteride exposure and risk for toxicity Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dutasteride and Fluconazole interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Dutasteride or Fluconazole need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Product Information: DIFLUCAN(R) oral tablets, oral suspension, intravenous infusion injection, fluconazole oral tablets, oral suspension, intravenous infusion injection. Roerig (per FDA), New York, NY, 2014. DailyMed
Keep reading about Fluconazole
Keep reading about Dutasteride
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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