Drug interactions
Amitriptyline + Diphenoxylate-atropine
Severity: Major
Amitriptyline and Diphenoxylate-atropine: major 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
Amitriptyline is strongly anticholinergic and sedating, and the atropine and diphenoxylate components add to this. The combination can cause constipation progressing to ileus, urinary retention, tachycardia, confusion and excess sedation.
What this interaction means in plain words
Amitriptyline and Diphenoxylate-atropine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Amitriptyline belongs to Central Nervous System; Diphenoxylate-atropine belongs to Gastrointestinal Tract.
Why it happens
Additive muscarinic blockade and additive CNS depression.
What to do
Avoid combining where possible, especially in older patients or those with ileus or urinary retention; if used, monitor bowel and bladder function and mental status.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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
- Amobarbital + Diphenoxylate-atropine Major
Other interactions of Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Frequently asked questions
Can I take Amitriptyline with Diphenoxylate-atropine?
MediHelp rates the interaction as major. Amitriptyline and Diphenoxylate-atropine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Amitriptyline is strongly anticholinergic and sedating, and the atropine and diphenoxylate components add to this. The combination can cause constipation progressing to ileus, urinary retention, tachycardia, confusion and excess sedation.
How serious is the interaction between Amitriptyline and Diphenoxylate-atropine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combining where possible, especially in older patients or those with ileus or urinary retention; if used, monitor bowel and bladder function and mental status.
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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