Drug interactions
Cyclobenzaprine + Venlafaxine
Severity: Major
Cyclobenzaprine and Venlafaxine: 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
Venlafaxine increases serotonin and noradrenaline, and cyclobenzaprine adds serotonergic activity, raising the risk of serotonin syndrome. Venlafaxine can also cause blood pressure increases and QT effects that overlap with cyclobenzaprine cardiac effects.
What this interaction means in plain words
Cyclobenzaprine and Venlafaxine 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; Venlafaxine belongs to Central Nervous System.
Why it happens
Additive serotonergic effects via reuptake inhibition and receptor activity.
What to do
Avoid if possible and use a non-serotonergic muscle relaxant. If used together, keep doses low and monitor for serotonin toxicity and heart rhythm effects.
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 Venlafaxine
- Isocarboxazid + Venlafaxine Contraindicated
- Methylene blue + Venlafaxine Contraindicated
- Phenelzine + Venlafaxine Contraindicated
- Procarbazine + Venlafaxine Contraindicated
- Rasagiline + Venlafaxine Contraindicated
- Safinamide + Venlafaxine Contraindicated
Frequently asked questions
Can I take Cyclobenzaprine with Venlafaxine?
MediHelp rates the interaction as major. Cyclobenzaprine and Venlafaxine 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. Venlafaxine increases serotonin and noradrenaline, and cyclobenzaprine adds serotonergic activity, raising the risk of serotonin syndrome. Venlafaxine can also cause blood pressure increases and QT effects that overlap with cyclobenzaprine cardiac effects.
How serious is the interaction between Cyclobenzaprine and Venlafaxine?
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 if possible and use a non-serotonergic muscle relaxant. If used together, keep doses low and monitor for serotonin toxicity and heart rhythm effects.
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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