Drug interactions
Diphenhydramine + Lormetazepam
Severity: Moderate
Diphenhydramine and Lormetazepam: 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 depress the central nervous system, so combined use increases daytime drowsiness, impaired coordination and the risk of falls. Older adults are especially vulnerable.
What this interaction means in plain words
Diphenhydramine and Lormetazepam 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 through GABA-A enhancement and H1 receptor blockade.
What to do
Avoid combined use for sleep where possible and warn about driving and alcohol. Use the lowest effective doses and reassess 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 Lormetazepam?
MediHelp rates the interaction as moderate. Diphenhydramine and Lormetazepam 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 depress the central nervous system, so combined use increases daytime drowsiness, impaired coordination and the risk of falls. Older adults are especially vulnerable.
How serious is the interaction between Diphenhydramine and Lormetazepam?
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 combined use for sleep where possible and warn about driving and alcohol. Use the lowest effective doses and reassess 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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