Drug interactions
Ergotamine + St john's wort
Severity: Moderate
Ergotamine and St john's wort: 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
St John's wort induces CYP3A4 and may lower ergotamine concentrations, which could reduce its efficacy in migraine. Variable induction makes exposure unpredictable, and loss of the inducer later may cause ergotamine levels to rise again, with a risk of ergotism.
What this interaction means in plain words
Ergotamine and St john's wort 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 intestinal and hepatic CYP3A4 (and P-glycoprotein) by St John's wort increases ergotamine metabolism.
What to do
Avoid the combination where possible and advise patients to stop St John's wort, recognizing that the inducing effect fades over about two weeks. Monitor migraine control and for vasospastic symptoms if the herb is stopped while ergotamine continues.
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 Ergotamine
- Almotriptan + Ergotamine Contraindicated
- Atazanavir + Ergotamine Contraindicated
- Clarithromycin + Ergotamine Contraindicated
- Cobicistat + Ergotamine Contraindicated
- Darunavir + Ergotamine Contraindicated
- Dihydroergotamine intranasal + Ergotamine Contraindicated
Frequently asked questions
Can I take Ergotamine with St john's wort?
MediHelp rates the interaction as moderate. Ergotamine and St john's wort 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. St John's wort induces CYP3A4 and may lower ergotamine concentrations, which could reduce its efficacy in migraine. Variable induction makes exposure unpredictable, and loss of the inducer later may cause ergotamine levels to rise again, with a risk of ergotism.
How serious is the interaction between Ergotamine and St john's wort?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible and advise patients to stop St John's wort, recognizing that the inducing effect fades over about two weeks. Monitor migraine control and for vasospastic symptoms if the herb is stopped while ergotamine continues.
What other medicines interact with Ergotamine?
MediHelp also lists interactions of Ergotamine with, for example, Almotriptan, Atazanavir, Clarithromycin. The full list is on the Ergotamine page.
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