Drug interactions
Diphenoxylate-atropine + Fentanyl
Severity: Major
Diphenoxylate-atropine and Fentanyl: major interaction.
Last updated Sources: US FDA label
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
Fentanyl is a potent opioid, and adding diphenoxylate increases central nervous system and respiratory depression. The atropine component and opioid effects on the gut also raise the risk of severe constipation, urinary retention and paralytic ileus.
What this interaction means in plain words
Diphenoxylate-atropine and Fentanyl 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.
Diphenoxylate-atropine belongs to Gastrointestinal Tract; Fentanyl belongs to Musculoskeletal.
Why it happens
Additive opioid-mediated central nervous system and gut motility effects plus antimuscarinic actions.
What to do
Avoid combined use where possible; if needed use the lowest doses and monitor sedation, respiratory rate and bowel and bladder function. Stop the antidiarrheal if abdominal distension or ileus develops.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Diphenoxylate-atropine and Fentanyl, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
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 Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl Major
Frequently asked questions
Can I take Diphenoxylate-atropine with Fentanyl?
MediHelp rates the interaction as major. Diphenoxylate-atropine and Fentanyl 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. Fentanyl is a potent opioid, and adding diphenoxylate increases central nervous system and respiratory depression. The atropine component and opioid effects on the gut also raise the risk of severe constipation, urinary retention and paralytic ileus.
How serious is the interaction between Diphenoxylate-atropine and Fentanyl?
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 combined use where possible; if needed use the lowest doses and monitor sedation, respiratory rate and bowel and bladder function. Stop the antidiarrheal if abdominal distension or ileus develops.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
