Drug interactions
Diphenoxylate-atropine + Homatropine
Severity: Moderate
Diphenoxylate-atropine and Homatropine: 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
Homatropine is an antimuscarinic, so use with atropine can cause additive anticholinergic effects such as dry mouth, constipation, urinary retention, and tachycardia. Risk depends on formulation and route.
What this interaction means in plain words
Diphenoxylate-atropine and Homatropine 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.
Diphenoxylate-atropine belongs to Gastrointestinal Tract; Homatropine belongs to Genitourinary.
Why it happens
Additive antimuscarinic receptor blockade.
What to do
Avoid duplicate antimuscarinic therapy when possible and monitor for anticholinergic effects, particularly in older adults.
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 Diphenoxylate-atropine
- Diphenoxylate-atropine + Isocarboxazid Contraindicated
- Diphenoxylate-atropine + Phenelzine Contraindicated
- Diphenoxylate-atropine + Tranylcypromine Contraindicated
- Alfentanil + Diphenoxylate-atropine Major
- Alvimopan + Diphenoxylate-atropine Major
- Amitriptyline + Diphenoxylate-atropine Major
Other interactions of Homatropine
- Amantadine + Homatropine Moderate
- Amitriptyline + Homatropine Moderate
- Atropine + Homatropine Moderate
- Benztropine + Homatropine Moderate
- Bethanechol + Homatropine Moderate
- Chlorpromazine + Homatropine Moderate
Frequently asked questions
Can I take Diphenoxylate-atropine with Homatropine?
MediHelp rates the interaction as moderate. Diphenoxylate-atropine and Homatropine 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. Homatropine is an antimuscarinic, so use with atropine can cause additive anticholinergic effects such as dry mouth, constipation, urinary retention, and tachycardia. Risk depends on formulation and route.
How serious is the interaction between Diphenoxylate-atropine and Homatropine?
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 duplicate antimuscarinic therapy when possible and monitor for anticholinergic effects, particularly in older adults.
What other medicines interact with Diphenoxylate-atropine?
MediHelp also lists interactions of Diphenoxylate-atropine with, for example, Isocarboxazid, Phenelzine, Tranylcypromine. The full list is on the Diphenoxylate-atropine page.
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