Drug interactions
Diphenhydramine + Olopatadine intranasal
Severity: Moderate
Diphenhydramine and Olopatadine intranasal: 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
Intranasal olopatadine can cause somnolence and diphenhydramine is strongly sedating. Together they may increase drowsiness and impair psychomotor performance.
What this interaction means in plain words
Diphenhydramine and Olopatadine intranasal 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 sedation from H1 antihistamine effects.
What to do
Avoid concurrent use of two antihistamines where possible; counsel patients about drowsiness and avoid driving.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Diphenhydramine and Olopatadine intranasal, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Olopatadine intranasal?
MediHelp rates the interaction as moderate. Diphenhydramine and Olopatadine intranasal 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. Intranasal olopatadine can cause somnolence and diphenhydramine is strongly sedating. Together they may increase drowsiness and impair psychomotor performance.
How serious is the interaction between Diphenhydramine and Olopatadine intranasal?
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 of two antihistamines where possible; counsel patients about drowsiness and avoid driving.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
