Drug interactions
Bazedoxifene-conjugated estrogens + Phenytoin
Severity: Major
Bazedoxifene-conjugated estrogens and Phenytoin: major 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
Phenytoin is a strong inducer of CYP3A4 and UGT enzymes and can substantially reduce exposure to conjugated estrogens and bazedoxifene. This may cause loss of symptom control and, because bazedoxifene protects the endometrium, may raise the risk of endometrial hyperplasia.
What this interaction means in plain words
Bazedoxifene-conjugated estrogens and Phenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Bazedoxifene-conjugated estrogens belongs to Endocrine; Phenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces CYP3A4 and glucuronidation, increasing clearance of estrogens and bazedoxifene.
What to do
Avoid the combination where possible and choose a non-inducing anticonvulsant. If it is used, monitor for breakthrough bleeding and recurrent menopausal symptoms and evaluate the endometrium promptly if bleeding occurs.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Bazedoxifene-conjugated estrogens
- Anastrozole + Bazedoxifene-conjugated estrogens Contraindicated
- Bazedoxifene-conjugated estrogens + Ospemifene Contraindicated
- Antithrombin alfa + Bazedoxifene-conjugated estrogens Major
- Antithrombin iii + Bazedoxifene-conjugated estrogens Major
- Bazedoxifene-conjugated estrogens + Bemiparin Major
- Bazedoxifene-conjugated estrogens + Carbamazepine Major
Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Frequently asked questions
Can I take Bazedoxifene-conjugated estrogens with Phenytoin?
MediHelp rates the interaction as major. Bazedoxifene-conjugated estrogens and Phenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Phenytoin is a strong inducer of CYP3A4 and UGT enzymes and can substantially reduce exposure to conjugated estrogens and bazedoxifene. This may cause loss of symptom control and, because bazedoxifene protects the endometrium, may raise the risk of endometrial hyperplasia.
How serious is the interaction between Bazedoxifene-conjugated estrogens and Phenytoin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible and choose a non-inducing anticonvulsant. If it is used, monitor for breakthrough bleeding and recurrent menopausal symptoms and evaluate the endometrium promptly if bleeding occurs.
What other medicines interact with Bazedoxifene-conjugated estrogens?
MediHelp also lists interactions of Bazedoxifene-conjugated estrogens with, for example, Anastrozole, Ospemifene, Antithrombin alfa. The full list is on the Bazedoxifene-conjugated estrogens page.
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