Drug interactions
Diphenhydramine + Estazolam
Severity: Moderate
Diphenhydramine and Estazolam: 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
Combining a sedating antihistamine with a benzodiazepine hypnotic increases drowsiness, dizziness and impairment of coordination and cognition. Risk of next-day impairment and falls is higher in older adults.
What this interaction means in plain words
Diphenhydramine and Estazolam 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 via GABA-A potentiation and central H1 receptor blockade.
What to do
Avoid using diphenhydramine as an additional sleep aid with estazolam and counsel against driving. Use the lowest estazolam dose 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 Estazolam?
MediHelp rates the interaction as moderate. Diphenhydramine and Estazolam 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. Combining a sedating antihistamine with a benzodiazepine hypnotic increases drowsiness, dizziness and impairment of coordination and cognition. Risk of next-day impairment and falls is higher in older adults.
How serious is the interaction between Diphenhydramine and Estazolam?
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 using diphenhydramine as an additional sleep aid with estazolam and counsel against driving. Use the lowest estazolam dose 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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