Drug interactions
Ephedrine + Promethazine
Severity: Minor
Ephedrine and Promethazine: minor 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
Ephedrine is a sympathomimetic stimulant while promethazine is sedating and can cause hypotension. The combination is sometimes used clinically and may counter promethazine-related hypotension, with no firmly established harmful interaction, though tachyarrhythmia is possible in susceptible patients.
What this interaction means in plain words
Ephedrine and Promethazine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Ephedrine belongs to Cardiovascular; Promethazine belongs to Respiratory.
Why it happens
Opposing pharmacodynamic effects of sympathomimetic stimulation and phenothiazine sedation and alpha blockade; no defined pharmacokinetic mechanism.
What to do
Monitor heart rate and blood pressure, particularly in patients with cardiovascular disease.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Promethazine
- Cabergoline + Promethazine Contraindicated
- Dopamine + Promethazine Contraindicated
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
Other interactions of Ephedrine
- Ephedrine + Isocarboxazid Contraindicated
- Ephedrine + Phenelzine Contraindicated
- Ephedrine + Procarbazine Contraindicated
- Ephedrine + Rasagiline Contraindicated
- Ephedrine + Selegiline Contraindicated
- Ephedrine + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Ephedrine with Promethazine?
MediHelp rates the interaction as minor. Ephedrine and Promethazine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Ephedrine is a sympathomimetic stimulant while promethazine is sedating and can cause hypotension. The combination is sometimes used clinically and may counter promethazine-related hypotension, with no firmly established harmful interaction, though tachyarrhythmia is possible in susceptible patients.
How serious is the interaction between Ephedrine and Promethazine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor heart rate and blood pressure, particularly in patients with cardiovascular disease.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Cabergoline, Dopamine, Ibutilide. The full list is on the Promethazine page.
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