Drug interactions
Diphenhydramine + Metoclopramide intranasal
Severity: Moderate
Diphenhydramine and Metoclopramide intranasal: 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
Metoclopramide can cause drowsiness and extrapyramidal effects. Diphenhydramine adds sedation and its anticholinergic effects may oppose metoclopramide's prokinetic action.
What this interaction means in plain words
Diphenhydramine and Metoclopramide intranasal 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 CNS depression and pharmacodynamic antagonism of gastrointestinal motility by anticholinergic activity.
What to do
Monitor for excess sedation and reduced prokinetic effect; consider a non-sedating antihistamine if one is needed.
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 Metoclopramide intranasal?
MediHelp rates the interaction as moderate. Diphenhydramine and Metoclopramide intranasal 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. Metoclopramide can cause drowsiness and extrapyramidal effects. Diphenhydramine adds sedation and its anticholinergic effects may oppose metoclopramide's prokinetic action.
How serious is the interaction between Diphenhydramine and Metoclopramide intranasal?
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 excess sedation and reduced prokinetic effect; consider a non-sedating antihistamine if one is needed.
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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