Drug interactions
Cyclobenzaprine + Phenobarbital
Severity: Moderate
Cyclobenzaprine and Phenobarbital: 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
Both agents depress the central nervous system, so combined use can cause marked drowsiness, ataxia and, at higher doses, respiratory depression. Phenobarbital is also a potent enzyme inducer that may reduce cyclobenzaprine concentrations.
What this interaction means in plain words
Cyclobenzaprine and Phenobarbital 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.
Why it happens
Additive CNS depression plus CYP induction by phenobarbital.
What to do
Monitor for oversedation and for reduced muscle relaxant effect; start with low cyclobenzaprine doses and advise against alcohol and driving.
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
Frequently asked questions
Can I take Cyclobenzaprine with Phenobarbital?
MediHelp rates the interaction as moderate. Cyclobenzaprine and Phenobarbital 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. Both agents depress the central nervous system, so combined use can cause marked drowsiness, ataxia and, at higher doses, respiratory depression. Phenobarbital is also a potent enzyme inducer that may reduce cyclobenzaprine concentrations.
How serious is the interaction between Cyclobenzaprine and Phenobarbital?
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 oversedation and for reduced muscle relaxant effect; start with low cyclobenzaprine doses and advise against alcohol and driving.
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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