Drug interactions
Diphenhydramine + Lemborexant
Severity: Moderate
Diphenhydramine and Lemborexant: 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, and combining them may increase somnolence and next-day impairment. Lemborexant labeling advises dose reconsideration when used with other CNS depressants.
What this interaction means in plain words
Diphenhydramine and Lemborexant 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; Lemborexant belongs to Central Nervous System.
Why it happens
Additive CNS depression from orexin receptor antagonism plus histamine H1 blockade.
What to do
Avoid concurrent diphenhydramine as a sleep aid with lemborexant. If both are required, reduce the dose where appropriate and counsel on driving and morning impairment.
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
Other interactions of Lemborexant
Frequently asked questions
Can I take Diphenhydramine with Lemborexant?
MediHelp rates the interaction as moderate. Diphenhydramine and Lemborexant 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, and combining them may increase somnolence and next-day impairment. Lemborexant labeling advises dose reconsideration when used with other CNS depressants.
How serious is the interaction between Diphenhydramine and Lemborexant?
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 concurrent diphenhydramine as a sleep aid with lemborexant. If both are required, reduce the dose where appropriate and counsel on driving and morning impairment.
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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