Drug interactions
Promethazine + Pseudoephedrine
Severity: Minor
Promethazine and Pseudoephedrine: 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
Promethazine's sedation can offset pseudoephedrine's stimulant effect, while both drugs may cause tachycardia or raise cardiac risk in predisposed patients. No robust evidence of a significant interaction exists for this pair.
What this interaction means in plain words
Promethazine and Pseudoephedrine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Promethazine belongs to Respiratory; Pseudoephedrine belongs to Respiratory.
Why it happens
Opposing CNS effects and possible additive cardiovascular stimulation; no firmly established mechanism.
What to do
Usually no change is needed. Monitor heart rate and blood pressure 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
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Other interactions of Pseudoephedrine
- Isocarboxazid + Pseudoephedrine Contraindicated
- Phenelzine + Pseudoephedrine Contraindicated
- Pseudoephedrine + Rasagiline Contraindicated
- Pseudoephedrine + Selegiline Contraindicated
- Pseudoephedrine + Selegiline transdermal Contraindicated
- Pseudoephedrine + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Promethazine with Pseudoephedrine?
MediHelp rates the interaction as minor. Promethazine and Pseudoephedrine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Promethazine's sedation can offset pseudoephedrine's stimulant effect, while both drugs may cause tachycardia or raise cardiac risk in predisposed patients. No robust evidence of a significant interaction exists for this pair.
How serious is the interaction between Promethazine and Pseudoephedrine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Usually no change is needed. Monitor heart rate and blood pressure in patients with cardiovascular disease.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Promethazine page.
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