Drug interactions
Diphenhydramine + Ipratropium
Severity: Moderate
Diphenhydramine and Ipratropium: 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 is a first-generation antihistamine with significant anticholinergic effects, and with ipratropium it may cause additive dry mouth, urinary retention, constipation, blurred vision and confusion. Older patients are most susceptible.
What this interaction means in plain words
Diphenhydramine and Ipratropium 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; Ipratropium belongs to Respiratory.
Why it happens
Additive muscarinic receptor blockade.
What to do
Monitor for anticholinergic effects and consider a non-sedating second-generation antihistamine in older adults or those with glaucoma or urinary retention.
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 Ipratropium
- Aclidinium + Ipratropium Moderate
- Benztropine + Ipratropium Moderate
- Bethanechol + Ipratropium Moderate
- Cevimeline + Ipratropium Moderate
- Chlorpromazine + Ipratropium Moderate
- Clomipramine + Ipratropium Moderate
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Ipratropium?
MediHelp rates the interaction as moderate. Diphenhydramine and Ipratropium 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 is a first-generation antihistamine with significant anticholinergic effects, and with ipratropium it may cause additive dry mouth, urinary retention, constipation, blurred vision and confusion. Older patients are most susceptible.
How serious is the interaction between Diphenhydramine and Ipratropium?
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 consider a non-sedating second-generation antihistamine in older adults or those with glaucoma or urinary retention.
What other medicines interact with Ipratropium?
MediHelp also lists interactions of Ipratropium with, for example, Aclidinium, Benztropine, Bethanechol. The full list is on the Ipratropium page.
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