Drug interactions
Clobazam + Diphenhydramine
Severity: Moderate
Clobazam and Diphenhydramine: 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
Clobazam is a benzodiazepine, and diphenhydramine is a sedating antihistamine. Together they increase drowsiness, slow psychomotor function and can contribute to respiratory depression. Falls and confusion are more likely in older adults.
What this interaction means in plain words
Clobazam and Diphenhydramine 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.
Clobazam belongs to Central Nervous System; Diphenhydramine belongs to Respiratory.
Why it happens
Additive central nervous system depression from GABA-A potentiation and central H1 receptor blockade.
What to do
Monitor for oversedation and avoid the antihistamine at bedtime in addition to the benzodiazepine where possible. Use a non-sedating antihistamine as an alternative.
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 Clobazam
- Amobarbital + Clobazam Major
- Buprenorphine + Clobazam Major
- Butorphanol + Clobazam Major
- Carisoprodol + Clobazam Major
- Chloral hydrate + Clobazam Major
- Clobazam + Clozapine Major
Frequently asked questions
Can I take Clobazam with Diphenhydramine?
MediHelp rates the interaction as moderate. Clobazam and Diphenhydramine 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. Clobazam is a benzodiazepine, and diphenhydramine is a sedating antihistamine. Together they increase drowsiness, slow psychomotor function and can contribute to respiratory depression. Falls and confusion are more likely in older adults.
How serious is the interaction between Clobazam and Diphenhydramine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for oversedation and avoid the antihistamine at bedtime in addition to the benzodiazepine where possible. Use a non-sedating antihistamine as an alternative.
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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