Drug interactions
Phenobarbital + Progesterone
Severity: Moderate
Phenobarbital and Progesterone: 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 a strong enzyme inducer and lowers progesterone exposure. This can reduce hormonal efficacy, including contraception and endometrial protection.
What this interaction means in plain words
Phenobarbital and Progesterone 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
Phenobarbital induces CYP3A4 and other hepatic enzymes, accelerating progesterone metabolism.
What to do
Monitor for breakthrough bleeding or loss of effect and consider dose increase or alternative therapy. Use a non-hormonal or non-enzyme-dependent contraceptive method such as an IUD.
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 Progesterone
Frequently asked questions
Can I take Phenobarbital with Progesterone?
MediHelp rates the interaction as moderate. Phenobarbital and Progesterone 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 a strong enzyme inducer and lowers progesterone exposure. This can reduce hormonal efficacy, including contraception and endometrial protection.
How serious is the interaction between Phenobarbital and Progesterone?
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 for breakthrough bleeding or loss of effect and consider dose increase or alternative therapy. Use a non-hormonal or non-enzyme-dependent contraceptive method such as an IUD.
What other medicines interact with Progesterone?
MediHelp also lists interactions of Progesterone with, for example, Apalutamide, Carbamazepine, Enzalutamide. The full list is on the Progesterone page.
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