Drug interactions
Promethazine + Zotepine
Severity: Moderate
Promethazine and Zotepine: 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 block dopamine receptors and are sedating, so combined use can increase extrapyramidal symptoms and drowsiness. Zotepine also lowers the seizure threshold and prolongs QT, which may be compounded by promethazine.
What this interaction means in plain words
Promethazine and Zotepine 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
Additive dopamine antagonism, CNS depression and anticholinergic effects, with possible additive QT prolongation.
What to do
Monitor for extrapyramidal symptoms, sedation and ECG changes in at-risk patients. Use the lowest effective doses.
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
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Frequently asked questions
Can I take Promethazine with Zotepine?
MediHelp rates the interaction as moderate. Promethazine and Zotepine 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 block dopamine receptors and are sedating, so combined use can increase extrapyramidal symptoms and drowsiness. Zotepine also lowers the seizure threshold and prolongs QT, which may be compounded by promethazine.
How serious is the interaction between Promethazine and Zotepine?
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 extrapyramidal symptoms, sedation and ECG changes in at-risk patients. Use the lowest effective doses.
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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