Drug interactions
Diazepam + Dimenhydrinate
Severity: Moderate
Diazepam and Dimenhydrinate: 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
Dimenhydrinate is a sedating antihistamine and adds to the CNS depression caused by diazepam. This can impair alertness, coordination and driving ability, with greater risk in older patients.
What this interaction means in plain words
Diazepam and Dimenhydrinate 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.
Diazepam belongs to Musculoskeletal; Dimenhydrinate belongs to Respiratory.
Why it happens
Additive CNS depression from H1-antihistamine and benzodiazepine GABA-A effects.
What to do
Warn patients about drowsiness and avoid driving or operating machinery; use the lowest effective doses and avoid in the elderly where possible.
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 Diazepam
Other interactions of Dimenhydrinate
Frequently asked questions
Can I take Diazepam with Dimenhydrinate?
MediHelp rates the interaction as moderate. Diazepam and Dimenhydrinate 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. Dimenhydrinate is a sedating antihistamine and adds to the CNS depression caused by diazepam. This can impair alertness, coordination and driving ability, with greater risk in older patients.
How serious is the interaction between Diazepam and Dimenhydrinate?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Warn patients about drowsiness and avoid driving or operating machinery; use the lowest effective doses and avoid in the elderly where possible.
What other medicines interact with Diazepam?
MediHelp also lists interactions of Diazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Alfentanil, Alprazolam. The full list is on the Diazepam page.
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