Drug interactions
Dihydroergotamine + Phenylephrine
Severity: Major
Dihydroergotamine and Phenylephrine: 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
Both drugs cause vasoconstriction, and together they can cause marked hypertension and peripheral or cerebral ischemia. The effect is most relevant with systemic phenylephrine.
What this interaction means in plain words
Dihydroergotamine and Phenylephrine 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.
Dihydroergotamine belongs to Central Nervous System; Phenylephrine belongs to Respiratory.
Why it happens
Additive alpha-adrenergic and serotonergic vasoconstriction.
What to do
Avoid systemic phenylephrine with dihydroergotamine. If unavoidable, monitor blood pressure and for signs of ischemia such as limb coldness or chest pain.
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 Phenylephrine
- Isocarboxazid + Phenylephrine Contraindicated
- Phenelzine + Phenylephrine Contraindicated
- Phenylephrine + Tranylcypromine Contraindicated
- Bromocriptine + Phenylephrine Major
- Cocaine + Phenylephrine Major
- Dihydroergotamine intranasal + Phenylephrine Major
Other interactions of Dihydroergotamine
- Almotriptan + Dihydroergotamine Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
- Dihydroergotamine + Dopamine Contraindicated
- Dihydroergotamine + Dronedarone Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Dihydroergotamine + Eletriptan Contraindicated
Frequently asked questions
Can I take Dihydroergotamine with Phenylephrine?
MediHelp rates the interaction as major. Dihydroergotamine and Phenylephrine 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. Both drugs cause vasoconstriction, and together they can cause marked hypertension and peripheral or cerebral ischemia. The effect is most relevant with systemic phenylephrine.
How serious is the interaction between Dihydroergotamine and Phenylephrine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid systemic phenylephrine with dihydroergotamine. If unavoidable, monitor blood pressure and for signs of ischemia such as limb coldness or chest pain.
What other medicines interact with Phenylephrine?
MediHelp also lists interactions of Phenylephrine with, for example, Isocarboxazid, Phenelzine, Tranylcypromine. The full list is on the Phenylephrine page.
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