Drug interactions
Estrogens, conjugated + Phenobarbitone
Severity: Moderate
Estrogens, conjugated and Phenobarbitone: moderate 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
Phenobarbitone induces hepatic enzymes and can lower circulating estrogen levels. This may reduce efficacy for menopausal symptoms and weaken endometrial protection balance.
What this interaction means in plain words
Estrogens, conjugated and Phenobarbitone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Estrogens, conjugated belongs to Musculoskeletal; Phenobarbitone belongs to Central Nervous System.
Why it happens
Induction of CYP3A4 and conjugation enzymes increases estrogen clearance.
What to do
Monitor symptom control and bleeding patterns and increase the estrogen dose if needed. Reassess the dose if the inducer is stopped.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Estrogens, conjugated
Other interactions of Phenobarbitone
- Cabotegravir + Phenobarbitone Contraindicated
- Doravirine + Phenobarbitone Contraindicated
- Isavuconazole + Phenobarbitone Contraindicated
- Darolutamide + Phenobarbitone Major
- Finerenone + Phenobarbitone Major
- Ivacaftor + Phenobarbitone Major
Frequently asked questions
Can I take Estrogens, conjugated with Phenobarbitone?
MediHelp rates the interaction as moderate. Estrogens, conjugated and Phenobarbitone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Phenobarbitone induces hepatic enzymes and can lower circulating estrogen levels. This may reduce efficacy for menopausal symptoms and weaken endometrial protection balance.
How serious is the interaction between Estrogens, conjugated and Phenobarbitone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor symptom control and bleeding patterns and increase the estrogen dose if needed. Reassess the dose if the inducer is stopped.
What other medicines interact with Estrogens, conjugated?
MediHelp also lists interactions of Estrogens, conjugated with, for example, Carbamazepine, Itraconazole, Ketoconazole. The full list is on the Estrogens, conjugated page.
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