This information on drug interactions with antimicrobials is intended for use as a guide and not as a complete reference source

Antimicrobial Interacting Drug Comment


































Drugs metabolised by CYP2D6 e.g.
TCAs, beta bockers, SSRIs, antiarrythmics, MAOI (Type B)

Terbinafine inhibits CYP2D6-mediated metabolism. This may be of clinical relevance for compounds predominantly metabolised by CYP2D6, e.g. certain members of the following drug classes, tricyclic antidepressants (TCAs), beta-blockers, selective serotonin reuptake inhibitors (SSRIs), antiarrhythmics (including class 1A, 1B and 1C) and monoamine oxidase inhibitors (MAO-Is) Type B. Consult individual product literature.


Aripiprazole: Terbinafine is predicted to increase aripiprazole exposure. Consult product literature.


Tamoxifen: Terbinafine may decrease serum concentrations of the active metabolites of tamoxifen. Avoid concurrent use.



Tricyclics: Terbinafine predicted to increase exposure to the tricyclics, potentially leading to toxicity. Monitor for increased tricyclic adverse effects such as dry mouth, blurred vision, urinary retention. Be aware that dose of tricyclic might need to be decreased. Risk of clinically important interactions if tricyclics are given within 3 months of stopping terbinafine.


Terbinafine: is predicted to increase galantamine exposure.


Fesoteridine:  Terbinafine is predicted to increase the exposure to fesoterodine.


Risperidone: Terbinafine is predicted increase risperidone concentrations.


Codeine: Reduced analgesic effect. Monitor for effect and modify analgesic therapy if required.


Terbinafine increased the clearance of ciclosporin by 15%.


Rare cases of changes in INR and/or prothrombin time have been reported in patients receiving terbinafine concomitantly with warfarin.


Terbinafine decreased the clearance of desipramine by 82%.




Fluconazole increased the Cmax and AUC of terbinafine by 52% and 69% respectively, due to inhibition of both CYP2C9 and CYP3A4 enzymes.

Similar increase in exposure may occur when other drugs which inhibit both CYP2C9 and CYP3A4 such as ketoconazole and amiodarone are concomitantly administered with terbinafine.

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