Drug interactions
Diphenhydramine + Zotepine
Severity: Moderate
Diphenhydramine 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
Zotepine is a sedating antipsychotic with anticholinergic activity, and diphenhydramine adds to both sedation and antimuscarinic effects. Zotepine also lowers the seizure threshold, so excess CNS effects deserve attention.
What this interaction means in plain words
Diphenhydramine 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 H1-antihistaminic, antimuscarinic and CNS depressant effects.
What to do
Monitor for oversedation, confusion, urinary retention and constipation. Avoid regular diphenhydramine use with zotepine, especially in older patients.
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 Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Zotepine?
MediHelp rates the interaction as moderate. Diphenhydramine 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. Zotepine is a sedating antipsychotic with anticholinergic activity, and diphenhydramine adds to both sedation and antimuscarinic effects. Zotepine also lowers the seizure threshold, so excess CNS effects deserve attention.
How serious is the interaction between Diphenhydramine 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 oversedation, confusion, urinary retention and constipation. Avoid regular diphenhydramine use with zotepine, especially in older patients.
What other medicines interact with Diphenhydramine?
MediHelp also lists interactions of Diphenhydramine with, for example, Alfentanil, Belladonna and opium, Benzhydrocodone / acetaminophen. The full list is on the Diphenhydramine page.
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