Drug interactions
Dutasteride + St john's wort
Severity: Moderate
Dutasteride and St john's wort: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
St John's wort induces CYP3A4 and may reduce dutasteride exposure, potentially weakening its therapeutic effect.
What this interaction means in plain words
Dutasteride and St john's wort can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Induction of CYP3A4 by St John's wort increases dutasteride metabolism.
What to do
Advise avoiding St John's wort or monitor for reduced clinical response to dutasteride.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Dutasteride
- Dutasteride + Levoketoconazole Moderate
- Dutasteride + Nefazodone Moderate
- Dutasteride + Rifampin Moderate
- Amobarbital + Dutasteride Minor
- Aprepitant + Dutasteride Minor
- Artemether / lumefantrine + Dutasteride Minor
Frequently asked questions
Can I take Dutasteride with St john's wort?
MediHelp rates the interaction as moderate. Dutasteride and St john's wort can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. St John's wort induces CYP3A4 and may reduce dutasteride exposure, potentially weakening its therapeutic effect.
How serious is the interaction between Dutasteride and St john's wort?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise avoiding St John's wort or monitor for reduced clinical response to dutasteride.
What other medicines interact with Dutasteride?
MediHelp also lists interactions of Dutasteride with, for example, Levoketoconazole, Nefazodone, Rifampin. The full list is on the Dutasteride page.
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