Drug interactions
Cinnarizine + Diphenhydramine
Severity: Moderate
Cinnarizine 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
Both are sedating antihistamines with anticholinergic properties, so combining them increases drowsiness, dizziness, confusion and impaired psychomotor performance.
What this interaction means in plain words
Cinnarizine 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.
Cinnarizine belongs to Respiratory; Diphenhydramine belongs to Respiratory.
Why it happens
Additive H1 antagonism with CNS depression and anticholinergic effects.
What to do
Avoid concurrent use where possible and counsel on driving and alcohol. Monitor older patients for confusion and falls.
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 Cinnarizine
- Alprazolam + Cinnarizine Moderate
- Amitriptyline + Cinnarizine Moderate
- Amobarbital + Cinnarizine Moderate
- Aripiprazole + Cinnarizine Moderate
- Azelastine-fluticasone + Cinnarizine Moderate
- Azelastine + Cinnarizine Moderate
Frequently asked questions
Can I take Cinnarizine with Diphenhydramine?
MediHelp rates the interaction as moderate. Cinnarizine 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. Both are sedating antihistamines with anticholinergic properties, so combining them increases drowsiness, dizziness, confusion and impaired psychomotor performance.
How serious is the interaction between Cinnarizine 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: Avoid concurrent use where possible and counsel on driving and alcohol. Monitor older patients for confusion and falls.
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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