Drug interactions
Diphenoxylate-atropine + Thioridazine
Severity: Moderate
Diphenoxylate-atropine and Thioridazine: 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
Thioridazine has strong anticholinergic and sedative properties, so with diphenoxylate-atropine there is additive sedation and anticholinergic toxicity such as constipation, urinary retention and confusion. Reduced gut motility may also alter absorption of oral thioridazine, and thioridazine carries significant QT risk that dehydration and electrolyte loss from diarrhea can worsen.
What this interaction means in plain words
Diphenoxylate-atropine and Thioridazine 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; Thioridazine belongs to Central Nervous System.
Why it happens
Additive antimuscarinic and CNS depressant effects, with possible reduced gastrointestinal absorption of thioridazine.
What to do
Monitor for sedation, anticholinergic effects and ileus, and check electrolytes and ECG if diarrhea is significant. Use the lowest dose and shortest duration of the antidiarrheal.
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 Thioridazine
- Abiraterone + Thioridazine Contraindicated
- Adagrasib + Thioridazine Contraindicated
- Amiodarone + Thioridazine Contraindicated
- Amisulpride + Thioridazine Contraindicated
- Amitriptyline + Thioridazine Contraindicated
- Amoxapine + Thioridazine Contraindicated
Frequently asked questions
Can I take Diphenoxylate-atropine with Thioridazine?
MediHelp rates the interaction as moderate. Diphenoxylate-atropine and Thioridazine 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. Thioridazine has strong anticholinergic and sedative properties, so with diphenoxylate-atropine there is additive sedation and anticholinergic toxicity such as constipation, urinary retention and confusion. Reduced gut motility may also alter absorption of oral thioridazine, and thioridazine carries significant QT risk that dehydration and electrolyte loss from diarrhea can worsen.
How serious is the interaction between Diphenoxylate-atropine and Thioridazine?
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 sedation, anticholinergic effects and ileus, and check electrolytes and ECG if diarrhea is significant. Use the lowest dose and shortest duration of the antidiarrheal.
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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