Drug interactions
Fenfluramine + Fentanyl
Severity: Moderate
Fenfluramine 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
Fenfluramine can cause somnolence and sedation, which may add to the CNS depression of fentanyl. Its serotonergic activity also raises a theoretical concern for serotonin syndrome with fentanyl.
What this interaction means in plain words
Fenfluramine 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.
Fenfluramine belongs to Central Nervous System; Fentanyl belongs to Musculoskeletal.
Why it happens
Additive CNS depression, with possible additive serotonergic effects.
What to do
Monitor for sedation and respiratory depression, and watch for signs of serotonin toxicity such as agitation, tremor, hyperthermia and clonus.
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 Fenfluramine
- Fenfluramine + Isocarboxazid Contraindicated
- Fenfluramine + Linezolid Contraindicated
- Fenfluramine + Phenelzine Contraindicated
- Fenfluramine + Selegiline Contraindicated
- Fenfluramine + Tranylcypromine Contraindicated
- Almotriptan + Fenfluramine Major
Frequently asked questions
Can I take Fenfluramine with Fentanyl?
MediHelp rates the interaction as moderate. Fenfluramine 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. Fenfluramine can cause somnolence and sedation, which may add to the CNS depression of fentanyl. Its serotonergic activity also raises a theoretical concern for serotonin syndrome with fentanyl.
How serious is the interaction between Fenfluramine 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 and respiratory depression, and watch for signs of serotonin toxicity such as agitation, tremor, hyperthermia and clonus.
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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