Drug interactions
Atropine + Promethazine
Severity: Moderate
Atropine and Promethazine: 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
Both drugs have antimuscarinic activity, so combined use can intensify dry mouth, blurred vision, constipation, urinary retention, tachycardia and confusion. Older patients are most vulnerable.
What this interaction means in plain words
Atropine and Promethazine 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.
Atropine belongs to Miscellaneous; Promethazine belongs to Respiratory.
Why it happens
Additive muscarinic receptor antagonism.
What to do
Monitor for anticholinergic toxicity such as confusion, urinary retention and tachycardia, and reduce doses if present.
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 Promethazine
- Cabergoline + Promethazine Contraindicated
- Dopamine + Promethazine Contraindicated
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
Other interactions of Atropine
- Atropine + Eluxadoline Major
- Atropine + Henbane Major
- Atropine + Pramlintide Major
- Abobotulinumtoxina + Atropine Moderate
- Aclidinium + Atropine Moderate
- Amantadine + Atropine Moderate
Frequently asked questions
Can I take Atropine with Promethazine?
MediHelp rates the interaction as moderate. Atropine and Promethazine 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. Both drugs have antimuscarinic activity, so combined use can intensify dry mouth, blurred vision, constipation, urinary retention, tachycardia and confusion. Older patients are most vulnerable.
How serious is the interaction between Atropine and Promethazine?
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 for anticholinergic toxicity such as confusion, urinary retention and tachycardia, and reduce doses if present.
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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