Drug interactions
Ethinylestradiol + Valproic acid
Severity: Moderate
Ethinylestradiol and Valproic acid: 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
Estrogen-containing contraceptives can lower serum valproate concentrations, which may reduce seizure control in patients who were previously stable. The effect is most relevant when an estrogen product is started or stopped.
What this interaction means in plain words
Ethinylestradiol and Valproic acid 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
Estrogens induce glucuronidation, which increases valproate clearance.
What to do
Monitor seizure frequency and consider checking valproate levels when starting or stopping ethinylestradiol, adjusting the valproate dose as needed. Consider non-hormonal or progestogen-only contraception where appropriate.
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 Valproic acid
- Ertapenem + Valproic acid Contraindicated
- Imipenem / cilastatin / relebactam + Valproic acid Contraindicated
- Imipenem / cilastatin + Valproic acid Contraindicated
- Meropenem / vaborbactam + Valproic acid Contraindicated
- Meropenem + Valproic acid Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Valproic acid Major
Frequently asked questions
Can I take Ethinylestradiol with Valproic acid?
MediHelp rates the interaction as moderate. Ethinylestradiol and Valproic acid 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. Estrogen-containing contraceptives can lower serum valproate concentrations, which may reduce seizure control in patients who were previously stable. The effect is most relevant when an estrogen product is started or stopped.
How serious is the interaction between Ethinylestradiol and Valproic acid?
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 seizure frequency and consider checking valproate levels when starting or stopping ethinylestradiol, adjusting the valproate dose as needed. Consider non-hormonal or progestogen-only contraception where appropriate.
What other medicines interact with Valproic acid?
MediHelp also lists interactions of Valproic acid with, for example, Ertapenem, Imipenem / cilastatin / relebactam, Imipenem / cilastatin. The full list is on the Valproic acid page.
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