Drug interactions
Cyclobenzaprine + Fluvoxamine
Severity: Major
Cyclobenzaprine and Fluvoxamine: 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
Both drugs enhance serotonergic transmission, risking serotonin syndrome. Fluvoxamine is a potent CYP1A2 inhibitor, and cyclobenzaprine is metabolized partly by CYP1A2, so cyclobenzaprine levels and its sedative and anticholinergic effects may increase.
What this interaction means in plain words
Cyclobenzaprine and Fluvoxamine 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.
Cyclobenzaprine belongs to Musculoskeletal; Fluvoxamine belongs to Central Nervous System.
Why it happens
Additive serotonin reuptake inhibition, with fluvoxamine inhibiting CYP1A2 and raising cyclobenzaprine exposure.
What to do
Avoid the combination if possible and choose a different muscle relaxant. If used, start with a low cyclobenzaprine dose and monitor for serotonin syndrome and excess sedation.
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 Cyclobenzaprine
- Cyclobenzaprine + Isocarboxazid Contraindicated
- Cyclobenzaprine + Linezolid Contraindicated
- Cyclobenzaprine + Phenelzine Contraindicated
- Cyclobenzaprine + Safinamide Contraindicated
- Cyclobenzaprine + Selegiline Contraindicated
- Cyclobenzaprine + Selegiline transdermal Contraindicated
Other interactions of Fluvoxamine
- Agomelatine + Fluvoxamine Contraindicated
- Alosetron + Fluvoxamine Contraindicated
- Fezolinetant + Fluvoxamine Contraindicated
- Fluvoxamine + Isocarboxazid Contraindicated
- Fluvoxamine + Mavacamten Contraindicated
- Fluvoxamine + Methylene blue Contraindicated
Frequently asked questions
Can I take Cyclobenzaprine with Fluvoxamine?
MediHelp rates the interaction as major. Cyclobenzaprine and Fluvoxamine 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. Both drugs enhance serotonergic transmission, risking serotonin syndrome. Fluvoxamine is a potent CYP1A2 inhibitor, and cyclobenzaprine is metabolized partly by CYP1A2, so cyclobenzaprine levels and its sedative and anticholinergic effects may increase.
How serious is the interaction between Cyclobenzaprine and Fluvoxamine?
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 and choose a different muscle relaxant. If used, start with a low cyclobenzaprine dose and monitor for serotonin syndrome and excess sedation.
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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