Drug interactions
Clemastine + Diphenoxylate
Severity: Moderate
Clemastine and Diphenoxylate: 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
Clemastine is a sedating first-generation antihistamine and diphenoxylate, usually combined with atropine, can cause drowsiness at higher doses. Together they may increase sedation and impair alertness. Additive anticholinergic effects from the atropine component may also occur.
What this interaction means in plain words
Clemastine and Diphenoxylate 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; Diphenoxylate belongs to Gastrointestinal Tract.
Why it happens
Additive central nervous system depression and anticholinergic effects.
What to do
Counsel patients to avoid driving or hazardous tasks until the response is known. Use the lowest effective doses and watch for excessive drowsiness, urinary retention and constipation.
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 Diphenoxylate
Frequently asked questions
Can I take Clemastine with Diphenoxylate?
MediHelp rates the interaction as moderate. Clemastine and Diphenoxylate 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 is a sedating first-generation antihistamine and diphenoxylate, usually combined with atropine, can cause drowsiness at higher doses. Together they may increase sedation and impair alertness. Additive anticholinergic effects from the atropine component may also occur.
How serious is the interaction between Clemastine and Diphenoxylate?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Counsel patients to avoid driving or hazardous tasks until the response is known. Use the lowest effective doses and watch for excessive drowsiness, urinary retention and constipation.
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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