Drug interactions
Fluconazole + Terbinafine
Severity: Moderate
Fluconazole 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
Fluconazole can raise terbinafine exposure because it inhibits several of the enzymes involved in terbinafine clearance. Higher terbinafine concentrations may increase gastrointestinal, hepatic and skin adverse effects, although the effect is usually modest.
What this interaction means in plain words
Fluconazole 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.
Fluconazole belongs to Anti Fungals; Terbinafine belongs to Anti Fungals.
Why it happens
Fluconazole inhibits CYP2C9, CYP2C19 and CYP3A4, which contribute to terbinafine metabolism, so terbinafine clearance falls.
What to do
Monitor for terbinafine adverse effects such as hepatotoxicity and taste or gastrointestinal disturbance. Check liver function if therapy is prolonged or symptoms appear.
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 Fluconazole
- Dihydroergotamine intranasal + Fluconazole Contraindicated
- Dihydroergotamine + Fluconazole Contraindicated
- Dofetilide + Fluconazole Contraindicated
- Domperidone + Fluconazole Contraindicated
- Dronedarone + Fluconazole Contraindicated
- Erythromycin + Fluconazole Contraindicated
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 Fluconazole with Terbinafine?
MediHelp rates the interaction as moderate. Fluconazole 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. Fluconazole can raise terbinafine exposure because it inhibits several of the enzymes involved in terbinafine clearance. Higher terbinafine concentrations may increase gastrointestinal, hepatic and skin adverse effects, although the effect is usually modest.
How serious is the interaction between Fluconazole 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 terbinafine adverse effects such as hepatotoxicity and taste or gastrointestinal disturbance. Check liver function if therapy is prolonged or symptoms appear.
What other medicines interact with Fluconazole?
MediHelp also lists interactions of Fluconazole with, for example, Dihydroergotamine intranasal, Dihydroergotamine, Dofetilide. The full list is on the Fluconazole page.
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