Drug interactions
Clemastine + Difenoxin
Severity: Moderate
Clemastine and Difenoxin: 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
Difenoxin is an opioid antidiarrheal related to diphenoxylate, and a sedating antihistamine may add to drowsiness and dizziness. Both also have anticholinergic effects, which may contribute to constipation and urinary retention.
What this interaction means in plain words
Clemastine and Difenoxin 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.
Clemastine belongs to Respiratory; Difenoxin belongs to Gastrointestinal Tract.
Why it happens
Additive CNS depression from the opioid and the sedating H1 antihistamine, with additive anticholinergic effects.
What to do
Use the lowest effective doses and monitor for sedation, constipation and urinary retention. Advise the patient to avoid alcohol and driving until the response is known.
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 Clemastine
Other interactions of Difenoxin
Frequently asked questions
Can I take Clemastine with Difenoxin?
MediHelp rates the interaction as moderate. Clemastine and Difenoxin 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. Difenoxin is an opioid antidiarrheal related to diphenoxylate, and a sedating antihistamine may add to drowsiness and dizziness. Both also have anticholinergic effects, which may contribute to constipation and urinary retention.
How serious is the interaction between Clemastine and Difenoxin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective doses and monitor for sedation, constipation and urinary retention. Advise the patient to avoid alcohol and driving until the response is known.
What other medicines interact with Clemastine?
MediHelp also lists interactions of Clemastine with, for example, Alfentanil, Benzhydrocodone / acetaminophen, Buprenorphine buccal. The full list is on the Clemastine page.
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