Drug interactions
Cyclobenzaprine + Fenfluramine
Severity: Moderate
Cyclobenzaprine and Fenfluramine: 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 increases serotonin release and cyclobenzaprine has serotonergic activity, so serotonin syndrome is a theoretical risk. Fenfluramine can also cause somnolence, which may add to cyclobenzaprine's sedation.
What this interaction means in plain words
Cyclobenzaprine and Fenfluramine 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.
Cyclobenzaprine belongs to Musculoskeletal; Fenfluramine belongs to Central Nervous System.
Why it happens
Possible additive serotonergic effects and additive sedation.
What to do
Monitor for agitation, tremor, hyperthermia, clonus and excessive sedation, especially after dose changes.
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 Cyclobenzaprine
- Cyclobenzaprine + Isocarboxazid Contraindicated
- Cyclobenzaprine + Linezolid Contraindicated
- Cyclobenzaprine + Phenelzine Contraindicated
- Cyclobenzaprine + Safinamide Contraindicated
- Cyclobenzaprine + Selegiline Contraindicated
- Cyclobenzaprine + Selegiline transdermal Contraindicated
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 Cyclobenzaprine with Fenfluramine?
MediHelp rates the interaction as moderate. Cyclobenzaprine and Fenfluramine 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 increases serotonin release and cyclobenzaprine has serotonergic activity, so serotonin syndrome is a theoretical risk. Fenfluramine can also cause somnolence, which may add to cyclobenzaprine's sedation.
How serious is the interaction between Cyclobenzaprine and Fenfluramine?
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 agitation, tremor, hyperthermia, clonus and excessive sedation, especially after dose changes.
What other medicines interact with Cyclobenzaprine?
MediHelp also lists interactions of Cyclobenzaprine with, for example, Isocarboxazid, Linezolid, Phenelzine. The full list is on the Cyclobenzaprine page.
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