Drug interactions
Amitriptyline + Diphenoxylate
Severity: Moderate
Amitriptyline 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
Diphenoxylate is an opioid antidiarrheal that can cause drowsiness, and amitriptyline adds to this sedation. Both agents slow gastrointestinal motility, so constipation and ileus are possible, especially at higher doses.
What this interaction means in plain words
Amitriptyline 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.
Amitriptyline belongs to Central Nervous System; Diphenoxylate belongs to Gastrointestinal Tract.
Why it happens
Additive CNS depression from opioid activity and amitriptyline sedation, with additive anticholinergic effects on the gut.
What to do
Monitor for oversedation and decreased bowel motility. Avoid exceeding the recommended diphenoxylate dose and counsel against alcohol and driving.
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 Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Other interactions of Diphenoxylate
Frequently asked questions
Can I take Amitriptyline with Diphenoxylate?
MediHelp rates the interaction as moderate. Amitriptyline 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. Diphenoxylate is an opioid antidiarrheal that can cause drowsiness, and amitriptyline adds to this sedation. Both agents slow gastrointestinal motility, so constipation and ileus are possible, especially at higher doses.
How serious is the interaction between Amitriptyline 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: Monitor for oversedation and decreased bowel motility. Avoid exceeding the recommended diphenoxylate dose and counsel against alcohol and driving.
What other medicines interact with Amitriptyline?
MediHelp also lists interactions of Amitriptyline with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Amitriptyline page.
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