Drug interactions
Atropine + Fentanyl
Severity: Moderate
Atropine 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
Both drugs slow gut motility and can cause urinary retention, so combined use may worsen constipation and, rarely, lead to paralytic ileus. Patients with prostatic enlargement or reduced bowel function are at greater risk.
What this interaction means in plain words
Atropine 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.
Atropine belongs to Miscellaneous; Fentanyl belongs to Musculoskeletal.
Why it happens
Additive reduction of gastrointestinal and bladder smooth muscle activity through opioid and anticholinergic effects.
What to do
Monitor bowel function and urinary output, and start a laxative regimen if therapy is prolonged. Reassess the need for the anticholinergic if retention or ileus symptoms appear.
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 Atropine
- Atropine + Eluxadoline Major
- Atropine + Henbane Major
- Atropine + Pramlintide Major
- Abobotulinumtoxina + Atropine Moderate
- Aclidinium + Atropine Moderate
- Amantadine + Atropine Moderate
Frequently asked questions
Can I take Atropine with Fentanyl?
MediHelp rates the interaction as moderate. Atropine 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. Both drugs slow gut motility and can cause urinary retention, so combined use may worsen constipation and, rarely, lead to paralytic ileus. Patients with prostatic enlargement or reduced bowel function are at greater risk.
How serious is the interaction between Atropine 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 bowel function and urinary output, and start a laxative regimen if therapy is prolonged. Reassess the need for the anticholinergic if retention or ileus symptoms appear.
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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