Drug interactions
Methylergonovine + Phenylephrine
Severity: Major
Methylergonovine and Phenylephrine: major interaction.
Last updated Sources: US FDA label
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 agents constrict blood vessels, so together they can cause severe hypertension and vasospasm. This is particularly relevant in the postpartum setting where methylergonovine is used.
What this interaction means in plain words
Methylergonovine 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.
Why it happens
Additive vasoconstriction through alpha-adrenergic stimulation and ergot-induced vascular smooth muscle contraction.
What to do
Avoid combining systemic vasopressors with methylergonovine where possible. If both are needed, monitor blood pressure closely and stop for severe hypertension or ischemic symptoms.
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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References
Other interactions of Phenylephrine
- Isocarboxazid + Phenylephrine Contraindicated
- Phenelzine + Phenylephrine Contraindicated
- Phenylephrine + Tranylcypromine Contraindicated
- Bromocriptine + Phenylephrine Major
- Cocaine + Phenylephrine Major
- Dihydroergotamine intranasal + Phenylephrine Major
Frequently asked questions
Can I take Methylergonovine with Phenylephrine?
MediHelp rates the interaction as major. Methylergonovine 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 agents constrict blood vessels, so together they can cause severe hypertension and vasospasm. This is particularly relevant in the postpartum setting where methylergonovine is used.
How serious is the interaction between Methylergonovine 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 combining systemic vasopressors with methylergonovine where possible. If both are needed, monitor blood pressure closely and stop for severe hypertension or ischemic symptoms.
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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