Drug interactions
Estradiol + Phenobarbital
Severity: Moderate
Estradiol and Phenobarbital: 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
Phenobarbital is an established enzyme inducer and can reduce estradiol exposure, leading to reduced efficacy. Effects develop over weeks and persist after discontinuation.
What this interaction means in plain words
Estradiol and Phenobarbital 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.
Why it happens
Induction of CYP3A4 and other enzymes, plus P-glycoprotein induction, increases estradiol clearance.
What to do
Monitor clinical response and consider a higher estradiol dose or a non-oral route. Reassess the dose if phenobarbital 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 Estradiol
- Anastrozole + Estradiol Contraindicated
- Estradiol + Fezolinetant Contraindicated
- Estradiol + Ospemifene Contraindicated
- Antithrombin alfa + Estradiol Major
- Antithrombin iii + Estradiol Major
- Estradiol + Exemestane Major
Frequently asked questions
Can I take Estradiol with Phenobarbital?
MediHelp rates the interaction as moderate. Estradiol and Phenobarbital 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. Phenobarbital is an established enzyme inducer and can reduce estradiol exposure, leading to reduced efficacy. Effects develop over weeks and persist after discontinuation.
How serious is the interaction between Estradiol and Phenobarbital?
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 clinical response and consider a higher estradiol dose or a non-oral route. Reassess the dose if phenobarbital is stopped.
What other medicines interact with Estradiol?
MediHelp also lists interactions of Estradiol with, for example, Anastrozole, Fezolinetant, Ospemifene. The full list is on the Estradiol page.
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