Drug interactions
Methylenedioxymethamphetamine + Phenylephrine
Severity: Major
Methylenedioxymethamphetamine and Phenylephrine: major interaction.
Last updated Sources: UK SmPC
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
MDMA causes marked release of norepinephrine, serotonin and dopamine, producing hypertension, tachycardia and hyperthermia. Phenylephrine adds direct vasoconstriction and may worsen blood pressure elevation, with a risk of hypertensive crisis, arrhythmia or cerebrovascular events.
What this interaction means in plain words
Methylenedioxymethamphetamine 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 sympathomimetic effects from MDMA-induced monoamine release and direct alpha-1 agonism by phenylephrine.
What to do
Avoid systemic phenylephrine, including oral decongestants, in patients who have recently taken MDMA. If a pressor is needed, use cautious titration with continuous blood pressure and ECG monitoring.
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 Methylenedioxymethamphetamine with Phenylephrine?
MediHelp rates the interaction as major. Methylenedioxymethamphetamine 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. MDMA causes marked release of norepinephrine, serotonin and dopamine, producing hypertension, tachycardia and hyperthermia. Phenylephrine adds direct vasoconstriction and may worsen blood pressure elevation, with a risk of hypertensive crisis, arrhythmia or cerebrovascular events.
How serious is the interaction between Methylenedioxymethamphetamine 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, including oral decongestants, in patients who have recently taken MDMA. If a pressor is needed, use cautious titration with continuous blood pressure and ECG monitoring.
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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