Tamoxifen and Terbinafine: Drug Interaction Guide

Quick answer: This combination requires caution. Tamoxifen and Terbinafine can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Tamoxifen interacts with Terbinafine

Terbinafine inhibits CYP2D6, which contributes to conversion of tamoxifen to the active metabolite endoxifen.

What you should do

Prefer an antifungal with minimal CYP2D6 inhibition when prolonged therapy is needed; discuss alternatives with oncology if unavoidable.

Key facts

Severity

Moderate — caution required

Mechanism

Terbinafine inhibits CYP2D6, which contributes to conversion of tamoxifen to the active metabolite endoxifen.

Action

Prefer an antifungal with minimal CYP2D6 inhibition when prolonged therapy is needed; discuss alternatives with oncology...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Tamoxifen and Terbinafine together?

With caution. Prefer an antifungal with minimal CYP2D6 inhibition when prolonged therapy is needed; discuss alternatives with oncology if unavoidable.

What is the severity of this interaction?

The interaction between Tamoxifen and Terbinafine is classified as Moderate — caution required. Terbinafine inhibits CYP2D6, which contributes to conversion of tamoxifen to the active metabolite endoxifen.

What should I do if I'm prescribed both?

Prefer an antifungal with minimal CYP2D6 inhibition when prolonged therapy is needed; discuss alternatives with oncology if unavoidable. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.