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Drug interactions

Anastrozole + Estrogens conjugated synthetic

Severity: Contraindicated

Anastrozole and Estrogens conjugated synthetic: contraindicated 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

Synthetic conjugated estrogens restore estrogenic stimulation that anastrozole is meant to remove. The therapeutic effect of anastrozole in breast cancer may be reduced.

What this interaction means in plain words

Anastrozole and Estrogens conjugated synthetic are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.

Evidence level: Moderate

Why it happens

Pharmacodynamic antagonism: exogenous estrogen counteracts aromatase inhibition.

What to do

Do not use together. Choose non-estrogen alternatives for menopausal symptoms.

What to ask your pharmacist

  • Is there an alternative to one of these two medicines for me?
  • If both are essential, who is monitoring me and how often?
  • Which symptoms mean I should stop and seek help straight away?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Anastrozole with Estrogens conjugated synthetic?

MediHelp rates the interaction as contraindicated. Anastrozole and Estrogens conjugated synthetic are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Synthetic conjugated estrogens restore estrogenic stimulation that anastrozole is meant to remove. The therapeutic effect of anastrozole in breast cancer may be reduced.

How serious is the interaction between Anastrozole and Estrogens conjugated synthetic?

MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not use together. Choose non-estrogen alternatives for menopausal symptoms.

What other medicines interact with Anastrozole?

MediHelp also lists interactions of Anastrozole with, for example, Bazedoxifene / conjugated estrogens, Bazedoxifene-conjugated estrogens, Conjugated estrogens. The full list is on the Anastrozole page.

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