Drug interactions
Diphenhydramine + Meperidine
Severity: Moderate
Diphenhydramine and Meperidine: 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
Diphenhydramine is a strongly sedating antihistamine that increases opioid sedation and impairs psychomotor performance. Anticholinergic effects may also add, with confusion, urinary retention, and falls in older adults.
What this interaction means in plain words
Diphenhydramine and Meperidine 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.
Diphenhydramine belongs to Respiratory; Meperidine belongs to Musculoskeletal.
Why it happens
Additive CNS depression and anticholinergic effects.
What to do
Avoid driving and alcohol, and consider a non-sedating antihistamine. Use lower doses and monitor older adults closely.
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 Meperidine
- Alvimopan + Meperidine Contraindicated
- Isocarboxazid + Meperidine Contraindicated
- Meperidine + Methylene blue Contraindicated
- Meperidine + Olanzapine / samidorphan Contraindicated
- Meperidine + Phenelzine Contraindicated
- Meperidine + Procarbazine Contraindicated
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Meperidine?
MediHelp rates the interaction as moderate. Diphenhydramine and Meperidine 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. Diphenhydramine is a strongly sedating antihistamine that increases opioid sedation and impairs psychomotor performance. Anticholinergic effects may also add, with confusion, urinary retention, and falls in older adults.
How serious is the interaction between Diphenhydramine and Meperidine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid driving and alcohol, and consider a non-sedating antihistamine. Use lower doses and monitor older adults closely.
What other medicines interact with Meperidine?
MediHelp also lists interactions of Meperidine with, for example, Alvimopan, Isocarboxazid, Methylene blue. The full list is on the Meperidine page.
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