Drug interactions
Grapefruit + Terbinafine
Severity: Minor
Grapefruit and Terbinafine: 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
Grapefruit inhibits intestinal CYP3A4 and might slightly increase terbinafine absorption or exposure. Because CYP3A4 is not a major route for terbinafine, the effect is negligible in practice.
What this interaction means in plain words
Grapefruit and Terbinafine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Grapefruit constituents inhibit intestinal CYP3A4, a minor pathway of terbinafine metabolism.
What to do
No restriction is typically necessary. Be aware of the theoretical effect if adverse effects occur.
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 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 Grapefruit with Terbinafine?
MediHelp rates the interaction as minor. Grapefruit and Terbinafine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Grapefruit inhibits intestinal CYP3A4 and might slightly increase terbinafine absorption or exposure. Because CYP3A4 is not a major route for terbinafine, the effect is negligible in practice.
How serious is the interaction between Grapefruit and Terbinafine?
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 restriction is typically necessary. Be aware of the theoretical effect if adverse effects occur.
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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