Drug interactions
Finasteride + Rifampin
Severity: Moderate
Finasteride and Rifampin: 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
Rifampin induces CYP3A4 and may lower finasteride concentrations, potentially reducing its effect on prostate size or hair loss.
What this interaction means in plain words
Finasteride and Rifampin 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
Rifampin induces CYP3A4, increasing finasteride clearance.
What to do
Monitor clinical response to finasteride during and after rifampin; efficacy may return gradually once rifampin is stopped.
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 Finasteride
- Finasteride + Levoketoconazole Moderate
- Finasteride + Nefazodone Moderate
- Finasteride + St john's wort Moderate
- Amobarbital + Finasteride Minor
- Aprepitant + Finasteride Minor
- Armodafinil + Finasteride Minor
Frequently asked questions
Can I take Finasteride with Rifampin?
MediHelp rates the interaction as moderate. Finasteride and Rifampin 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. Rifampin induces CYP3A4 and may lower finasteride concentrations, potentially reducing its effect on prostate size or hair loss.
How serious is the interaction between Finasteride and Rifampin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor clinical response to finasteride during and after rifampin; efficacy may return gradually once rifampin is stopped.
What other medicines interact with Finasteride?
MediHelp also lists interactions of Finasteride with, for example, Levoketoconazole, Nefazodone, St john's wort. The full list is on the Finasteride page.
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