Drug interactions
Dutasteride + Primidone
Severity: Minor
Dutasteride and Primidone: minor 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
Primidone, and its active metabolite phenobarbital, induces hepatic and intestinal CYP3A4, which is a main route of dutasteride clearance. Dutasteride exposure may fall, potentially weakening its effect on prostate size and symptoms. The clinical importance is probably small.
What this interaction means in plain words
Dutasteride and Primidone have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Dutasteride belongs to Genitourinary; Primidone belongs to Central Nervous System.
Why it happens
Enzyme induction of CYP3A4 by primidone/phenobarbital increases the metabolism of dutasteride.
What to do
No routine dose change is needed; if the response to dutasteride appears reduced in a patient on long-term primidone, reassess symptoms and PSA response.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Dutasteride
- Dutasteride + Levoketoconazole Moderate
- Dutasteride + Nefazodone Moderate
- Dutasteride + Rifampin Moderate
- Dutasteride + St john's wort Moderate
- Amobarbital + Dutasteride Minor
- Aprepitant + Dutasteride Minor
Other interactions of Primidone
- Lorlatinib + Primidone Contraindicated
- Lurasidone + Primidone Contraindicated
- Primidone + Ranolazine Contraindicated
- Primidone + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Primidone + Voriconazole Contraindicated
- Abiraterone + Primidone Major
Frequently asked questions
Can I take Dutasteride with Primidone?
MediHelp rates the interaction as minor. Dutasteride and Primidone have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Primidone, and its active metabolite phenobarbital, induces hepatic and intestinal CYP3A4, which is a main route of dutasteride clearance. Dutasteride exposure may fall, potentially weakening its effect on prostate size and symptoms. The clinical importance is probably small.
How serious is the interaction between Dutasteride and Primidone?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine dose change is needed; if the response to dutasteride appears reduced in a patient on long-term primidone, reassess symptoms and PSA response.
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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