Drug interactions
Dihydroergotamine intranasal + Metronidazole
Severity: Moderate
Dihydroergotamine intranasal and Metronidazole: 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
Intranasal dihydroergotamine has lower bioavailability than injection, but ergot toxicity with CYP3A4 inhibition is still a concern. Metronidazole is a weak inhibitor at most, so the risk is theoretical.
What this interaction means in plain words
Dihydroergotamine intranasal and Metronidazole 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
Possible weak CYP3A4 inhibition by metronidazole reducing dihydroergotamine clearance.
What to do
Counsel patients to report cold or numb extremities, chest pain or severe nausea and stop dihydroergotamine if they occur. Use the lowest effective dose.
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 Metronidazole
- Ethanol + Metronidazole Contraindicated
- Metronidazole + Pimozide Contraindicated
- Amiodarone + Metronidazole Major
- Disulfiram + Metronidazole Major
- Ergotamine + Metronidazole Major
- Lomitapide + Metronidazole Major
Frequently asked questions
Can I take Dihydroergotamine intranasal with Metronidazole?
MediHelp rates the interaction as moderate. Dihydroergotamine intranasal and Metronidazole 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. Intranasal dihydroergotamine has lower bioavailability than injection, but ergot toxicity with CYP3A4 inhibition is still a concern. Metronidazole is a weak inhibitor at most, so the risk is theoretical.
How serious is the interaction between Dihydroergotamine intranasal and Metronidazole?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Counsel patients to report cold or numb extremities, chest pain or severe nausea and stop dihydroergotamine if they occur. Use the lowest effective dose.
What other medicines interact with Metronidazole?
MediHelp also lists interactions of Metronidazole with, for example, Ethanol, Pimozide, Amiodarone. The full list is on the Metronidazole page.
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