Drug interactions
Diphenoxylate-atropine + Trifluoperazine
Severity: Moderate
Diphenoxylate-atropine and Trifluoperazine: 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
Both agents add to CNS depression, and the anticholinergic activity of atropine and trifluoperazine can accumulate, causing dry mouth, constipation, urinary retention, blurred vision and confusion. Anticholinergics may also reduce the absorption or effect of oral phenothiazines, although this is of uncertain clinical importance.
What this interaction means in plain words
Diphenoxylate-atropine and Trifluoperazine 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.
Why it happens
Additive CNS depressant and anticholinergic effects, with possible reduced phenothiazine absorption from slowed gastrointestinal motility.
What to do
Monitor for oversedation, anticholinergic toxicity and loss of antipsychotic control. Reduce the dose or stop diphenoxylate-atropine if constipation, ileus or urinary retention develop, particularly in older patients.
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
Frequently asked questions
Can I take Diphenoxylate-atropine with Trifluoperazine?
MediHelp rates the interaction as moderate. Diphenoxylate-atropine and Trifluoperazine 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. Both agents add to CNS depression, and the anticholinergic activity of atropine and trifluoperazine can accumulate, causing dry mouth, constipation, urinary retention, blurred vision and confusion. Anticholinergics may also reduce the absorption or effect of oral phenothiazines, although this is of uncertain clinical importance.
How serious is the interaction between Diphenoxylate-atropine and Trifluoperazine?
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 oversedation, anticholinergic toxicity and loss of antipsychotic control. Reduce the dose or stop diphenoxylate-atropine if constipation, ileus or urinary retention develop, particularly in older patients.
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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