Drug interactions
Perphenazine + Terbinafine
Severity: Moderate
Perphenazine 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
Perphenazine is primarily metabolized by CYP2D6, and terbinafine can substantially increase its levels. This may cause extrapyramidal symptoms, sedation, hypotension and QT prolongation.
What this interaction means in plain words
Perphenazine 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.
Perphenazine belongs to Central Nervous System; Terbinafine belongs to Anti Fungals.
Why it happens
Terbinafine inhibits CYP2D6, decreasing perphenazine metabolism.
What to do
Monitor for extrapyramidal and sedative effects and reduce the perphenazine dose if needed. Consider an alternative antifungal when feasible.
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
Other interactions of Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Perphenazine with Terbinafine?
MediHelp rates the interaction as moderate. Perphenazine 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. Perphenazine is primarily metabolized by CYP2D6, and terbinafine can substantially increase its levels. This may cause extrapyramidal symptoms, sedation, hypotension and QT prolongation.
How serious is the interaction between Perphenazine 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 extrapyramidal and sedative effects and reduce the perphenazine dose if needed. Consider an alternative antifungal when feasible.
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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