Drug interactions
Terbinafine + Timolol
Severity: Moderate
Terbinafine and Timolol: 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
Oral timolol is metabolized mainly by CYP2D6, so terbinafine may increase systemic levels and beta-blocking effects. This can result in bradycardia and hypotension.
What this interaction means in plain words
Terbinafine and Timolol 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 belongs to Anti Fungals; Timolol belongs to Cardiovascular.
Why it happens
Terbinafine inhibits CYP2D6-mediated metabolism of timolol.
What to do
Monitor heart rate and blood pressure and reduce the timolol dose if bradycardia or hypotension occurs.
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 Timolol
- Acebutolol + Timolol Major
- Albuterol + Timolol Major
- Aldesleukin + Timolol Major
- Amifostine + Timolol Major
- Amiodarone + Timolol Major
- Arformoterol + Timolol Major
Frequently asked questions
Can I take Terbinafine with Timolol?
MediHelp rates the interaction as moderate. Terbinafine and Timolol 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. Oral timolol is metabolized mainly by CYP2D6, so terbinafine may increase systemic levels and beta-blocking effects. This can result in bradycardia and hypotension.
How serious is the interaction between Terbinafine and Timolol?
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 heart rate and blood pressure and reduce the timolol dose if bradycardia or hypotension occurs.
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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