letrozole · Medicine question

Why should tamoxifen and letrozole not be taken together?

iatroX medicinesPublished 8 November 2026

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Tamoxifen and letrozole should not be taken together because tamoxifen may diminish letrozole’s pharmacological action and has been shown to substantially decrease its plasma concentrations.

Sources for this answer

Femara 2.5 mg TabletsNovartis Pharmaceuticals UK Ltd · emc · SmPC §4.5 Interaction with other medicinal products · Version 35Document updated 2 September 2025

Sources checked 8 November 2026

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