Drug interactions
Diphenhydramine + Droperidol
Severity: Moderate
Diphenhydramine and Droperidol: 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 agents cause sedation, so concurrent use increases drowsiness and psychomotor impairment. Droperidol also prolongs the QT interval, and the combination adds anticholinergic burden in vulnerable patients.
What this interaction means in plain words
Diphenhydramine and Droperidol 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 from H1 antagonism and dopamine blockade, with additional anticholinergic effects.
What to do
Use the lowest effective doses and monitor sedation level and respiratory status. Obtain an ECG and correct electrolytes if other QT-prolonging risks are 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 Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Droperidol?
MediHelp rates the interaction as moderate. Diphenhydramine and Droperidol 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 agents cause sedation, so concurrent use increases drowsiness and psychomotor impairment. Droperidol also prolongs the QT interval, and the combination adds anticholinergic burden in vulnerable patients.
How serious is the interaction between Diphenhydramine and Droperidol?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective doses and monitor sedation level and respiratory status. Obtain an ECG and correct electrolytes if other QT-prolonging risks are present.
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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