Drug interactions
Rifampin + Terbinafine
Severity: Moderate
Rifampin and Terbinafine: 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 lowers terbinafine plasma concentrations, with documented reductions in exposure. This may result in treatment failure of fungal infections.
What this interaction means in plain words
Rifampin and Terbinafine 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 hepatic CYP enzymes, increasing terbinafine clearance.
What to do
Monitor for antifungal response and consider increasing the terbinafine dose or choosing an alternative if the response is inadequate.
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 Terbinafine
- Terbinafine + Thioridazine Contraindicated
- Desipramine + Terbinafine Major
- Eliglustat + Terbinafine Major
- Flecainide + Terbinafine Major
- Imipramine + Terbinafine Major
- Maprotiline + Terbinafine Major
Frequently asked questions
Can I take Rifampin with Terbinafine?
MediHelp rates the interaction as moderate. Rifampin and Terbinafine 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 lowers terbinafine plasma concentrations, with documented reductions in exposure. This may result in treatment failure of fungal infections.
How serious is the interaction between Rifampin and Terbinafine?
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 for antifungal response and consider increasing the terbinafine dose or choosing an alternative if the response is inadequate.
What other medicines interact with Terbinafine?
MediHelp also lists interactions of Terbinafine with, for example, Thioridazine, Desipramine, Eliglustat. The full list is on the Terbinafine page.
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