Drug interactions
Difenoxin + Fentanyl
Severity: Moderate
Difenoxin and Fentanyl: 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
Difenoxin is an opioid-related antidiarrheal and the active metabolite of diphenoxylate, and it adds to the CNS depressant effects of fentanyl. Excess sedation, respiratory depression and severe constipation are possible.
What this interaction means in plain words
Difenoxin and Fentanyl 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.
Difenoxin belongs to Gastrointestinal Tract; Fentanyl belongs to Musculoskeletal.
Why it happens
Additive opioid-mediated CNS depression and reduced gastrointestinal motility.
What to do
Monitor for sedation, respiratory depression and constipation, and avoid exceeding recommended doses of difenoxin.
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 Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl Major
Other interactions of Difenoxin
Frequently asked questions
Can I take Difenoxin with Fentanyl?
MediHelp rates the interaction as moderate. Difenoxin and Fentanyl 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. Difenoxin is an opioid-related antidiarrheal and the active metabolite of diphenoxylate, and it adds to the CNS depressant effects of fentanyl. Excess sedation, respiratory depression and severe constipation are possible.
How serious is the interaction between Difenoxin and Fentanyl?
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, respiratory depression and constipation, and avoid exceeding recommended doses of difenoxin.
What other medicines interact with Fentanyl?
MediHelp also lists interactions of Fentanyl with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Fentanyl page.
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