Drug interactions
Ethinylestradiol + Griseofulvin
Severity: Major
Ethinylestradiol and Griseofulvin: 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
Griseofulvin may reduce the effectiveness of combined hormonal contraceptives, with reports of breakthrough bleeding and contraceptive failure. The effect is thought to arise from enzyme induction.
What this interaction means in plain words
Ethinylestradiol and Griseofulvin 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.
Why it happens
Griseofulvin induces hepatic CYP3A4, increasing metabolism of ethinylestradiol.
What to do
Advise an additional non-hormonal contraceptive method during treatment and for at least one month after stopping griseofulvin. Consider an alternative antifungal where appropriate.
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 Griseofulvin
Frequently asked questions
Can I take Ethinylestradiol with Griseofulvin?
MediHelp rates the interaction as major. Ethinylestradiol and Griseofulvin 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. Griseofulvin may reduce the effectiveness of combined hormonal contraceptives, with reports of breakthrough bleeding and contraceptive failure. The effect is thought to arise from enzyme induction.
How serious is the interaction between Ethinylestradiol and Griseofulvin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise an additional non-hormonal contraceptive method during treatment and for at least one month after stopping griseofulvin. Consider an alternative antifungal where appropriate.
What other medicines interact with Griseofulvin?
MediHelp also lists interactions of Griseofulvin with, for example, Cyclosporine, Cyclosporin, Desogestrel-ethinyl estradiol. The full list is on the Griseofulvin page.
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