Drug interactions
Diphenhydramine + Glycopyrronium
Severity: Moderate
Diphenhydramine and Glycopyrronium: 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
Diphenhydramine has strong anticholinergic properties, so with glycopyrronium it can cause additive dry mouth, urinary retention, constipation, tachycardia, blurred vision and confusion, particularly in older adults.
What this interaction means in plain words
Diphenhydramine and Glycopyrronium 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.
Diphenhydramine belongs to Respiratory; Glycopyrronium belongs to Respiratory.
Why it happens
Additive pharmacodynamic antimuscarinic effects.
What to do
Monitor for anticholinergic effects and mental status; prefer a less anticholinergic antihistamine such as a second-generation agent where appropriate.
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 Glycopyrronium, 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 Glycopyrronium
- Clozapine + Glycopyrronium Major
- Glycopyrronium + Potassium chloride Major
- Abobotulinumtoxina + Glycopyrronium Moderate
- Aclidinium + Glycopyrronium Moderate
- Amantadine + Glycopyrronium Moderate
- Amitriptyline + Glycopyrronium Moderate
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Glycopyrronium?
MediHelp rates the interaction as moderate. Diphenhydramine and Glycopyrronium 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. Diphenhydramine has strong anticholinergic properties, so with glycopyrronium it can cause additive dry mouth, urinary retention, constipation, tachycardia, blurred vision and confusion, particularly in older adults.
How serious is the interaction between Diphenhydramine and Glycopyrronium?
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 anticholinergic effects and mental status; prefer a less anticholinergic antihistamine such as a second-generation agent where appropriate.
What other medicines interact with Glycopyrronium?
MediHelp also lists interactions of Glycopyrronium with, for example, Clozapine, Potassium chloride, Abobotulinumtoxina. The full list is on the Glycopyrronium 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.
