Drug interactions
Doxepin + Terbinafine
Severity: Moderate
Doxepin 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
Terbinafine strongly inhibits CYP2D6 and can increase doxepin concentrations. This may cause excessive sedation, anticholinergic effects and cardiac conduction changes.
What this interaction means in plain words
Doxepin 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.
Doxepin belongs to Dermatology; Terbinafine belongs to Anti Fungals.
Why it happens
Terbinafine inhibits CYP2D6-mediated metabolism of doxepin.
What to do
Monitor for tricyclic toxicity and consider a lower doxepin dose; obtain an ECG in patients with cardiac risk.
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 Doxepin
- Doxepin + Isocarboxazid Contraindicated
- Doxepin + Phenelzine Contraindicated
- Doxepin + Procarbazine Contraindicated
- Doxepin + Safinamide Contraindicated
- Doxepin + Selegiline Contraindicated
- Doxepin + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Doxepin with Terbinafine?
MediHelp rates the interaction as moderate. Doxepin 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. Terbinafine strongly inhibits CYP2D6 and can increase doxepin concentrations. This may cause excessive sedation, anticholinergic effects and cardiac conduction changes.
How serious is the interaction between Doxepin 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 tricyclic toxicity and consider a lower doxepin dose; obtain an ECG in patients with cardiac risk.
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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