Drug interactions
Methoxyflurane + Phenylephrine
Severity: Moderate
Methoxyflurane and Phenylephrine: 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
Halogenated anesthetics like methoxyflurane may sensitize the myocardium to catecholamines, which could provoke ventricular arrhythmias and hypertension when used with adrenergic drugs. The combination is of limited modern relevance, but low-dose analgesic use is also possible.
What this interaction means in plain words
Methoxyflurane and Phenylephrine 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
Anesthetic-induced myocardial sensitization to catecholamines combined with adrenergic vasoconstriction.
What to do
Monitor ECG and blood pressure, and use the lowest effective phenylephrine 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 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 Methoxyflurane with Phenylephrine?
MediHelp rates the interaction as moderate. Methoxyflurane and Phenylephrine 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. Halogenated anesthetics like methoxyflurane may sensitize the myocardium to catecholamines, which could provoke ventricular arrhythmias and hypertension when used with adrenergic drugs. The combination is of limited modern relevance, but low-dose analgesic use is also possible.
How serious is the interaction between Methoxyflurane and Phenylephrine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor ECG and blood pressure, and use the lowest effective phenylephrine dose.
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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