Drug interactions
Cyproheptadine + Fentanyl transmucosal
Severity: Major
Cyproheptadine and Fentanyl transmucosal: 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
Transmucosal fentanyl has rapid onset and potent opioid effects, and cyproheptadine adds sedation and anticholinergic effects. Together they can increase the risk of respiratory depression, profound sedation, constipation and urinary retention.
What this interaction means in plain words
Cyproheptadine and Fentanyl transmucosal 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.
Why it happens
Additive CNS and respiratory depression from opioid agonism and H1 antagonism, with additive anticholinergic effects.
What to do
Avoid the combination if possible, or use reduced doses with close monitoring of sedation and breathing. Monitor for constipation and urinary retention.
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?
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References
Other interactions of Cyproheptadine
- Cyproheptadine + Isocarboxazid Contraindicated
- Cyproheptadine + Phenelzine Contraindicated
- Cyproheptadine + Tranylcypromine Contraindicated
- Alfentanil + Cyproheptadine Major
- Belladonna and opium + Cyproheptadine Major
- Benzhydrocodone / acetaminophen + Cyproheptadine Major
Frequently asked questions
Can I take Cyproheptadine with Fentanyl transmucosal?
MediHelp rates the interaction as major. Cyproheptadine and Fentanyl transmucosal 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. Transmucosal fentanyl has rapid onset and potent opioid effects, and cyproheptadine adds sedation and anticholinergic effects. Together they can increase the risk of respiratory depression, profound sedation, constipation and urinary retention.
How serious is the interaction between Cyproheptadine and Fentanyl transmucosal?
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 the combination if possible, or use reduced doses with close monitoring of sedation and breathing. Monitor for constipation and urinary retention.
What other medicines interact with Cyproheptadine?
MediHelp also lists interactions of Cyproheptadine with, for example, Isocarboxazid, Phenelzine, Tranylcypromine. The full list is on the Cyproheptadine page.
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