Cyclopentolate Ophthalmic and Alfentanil: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Alfentanil
No brand names on recordCyclopentolate Ophthalmic
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increased risk of urinary retention and/or severe constipation, which may lead to paralytic ileus
Interaction Deep Dive
Concomitant use of ALfentanil with anticholinergics may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor patients for signs of urinary retention or reduced gastric motility when ALfentanil is used concomitantly with anticholinergic drugs1.
Why it happens (mechanism)
Unknown
Common questions
Can I take Cyclopentolate Ophthalmic and Alfentanil together?
An increased risk of urinary retention and/or severe constipation, which may lead to paralytic ileus Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cyclopentolate Ophthalmic and Alfentanil interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Cyclopentolate Ophthalmic or Alfentanil need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: Alfentanil HCl intravenous injection, alfentanil HCl intravenous injection. Rising Pharma Holdings, Inc (per FDA), East Brunswick, NJ, 2025.
Keep reading about Alfentanil
Keep reading about Cyclopentolate Ophthalmic
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist