Drug interactions
Diphenhydramine + Temazepam
Severity: Major
Diphenhydramine and Temazepam: major interaction.
Last updated Sources: US FDA label
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 drugs cause sedation, and using them together increases drowsiness, next-day impairment, falls and cognitive effects. Respiratory depression is possible, especially in older patients or those with lung disease.
What this interaction means in plain words
Diphenhydramine and Temazepam can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Diphenhydramine belongs to Respiratory; Temazepam belongs to Central Nervous System.
Why it happens
Additive CNS depression from GABA-A potentiation and central H1 blockade.
What to do
Avoid combined use for sleep where possible, particularly in older adults. If unavoidable, use the lowest doses and monitor sedation and breathing.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Diphenhydramine
Other interactions of Temazepam
- Alprazolam + Temazepam Major
- Amobarbital + Temazepam Major
- Buprenorphine + Temazepam Major
- Butorphanol + Temazepam Major
- Carisoprodol + Temazepam Major
- Chloral hydrate + Temazepam Major
Frequently asked questions
Can I take Diphenhydramine with Temazepam?
MediHelp rates the interaction as major. Diphenhydramine and Temazepam can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both drugs cause sedation, and using them together increases drowsiness, next-day impairment, falls and cognitive effects. Respiratory depression is possible, especially in older patients or those with lung disease.
How serious is the interaction between Diphenhydramine and Temazepam?
MediHelp rates it major, 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, particularly in older adults. If unavoidable, use the lowest doses and monitor sedation and breathing.
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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