Drug interactions
Cyclobenzaprine + Perphenazine
Severity: Moderate
Cyclobenzaprine and Perphenazine: 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 drugs are sedating and anticholinergic, so combined use can cause marked drowsiness, dry mouth, constipation, urinary retention and confusion. Both may also prolong the QT interval, and perphenazine can inhibit CYP2D6, which participates in cyclobenzaprine metabolism.
What this interaction means in plain words
Cyclobenzaprine and Perphenazine 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; Perphenazine belongs to Central Nervous System.
Why it happens
Additive CNS depression, anticholinergic burden and QT effects, with possible CYP2D6 inhibition by perphenazine.
What to do
Monitor for sedation and anticholinergic toxicity, particularly in older adults, and use the lowest effective doses. Check an ECG if QT risk factors or other QT-prolonging drugs are present.
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 Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Cyclobenzaprine with Perphenazine?
MediHelp rates the interaction as moderate. Cyclobenzaprine and Perphenazine 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 drugs are sedating and anticholinergic, so combined use can cause marked drowsiness, dry mouth, constipation, urinary retention and confusion. Both may also prolong the QT interval, and perphenazine can inhibit CYP2D6, which participates in cyclobenzaprine metabolism.
How serious is the interaction between Cyclobenzaprine and Perphenazine?
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 anticholinergic toxicity, particularly in older adults, and use the lowest effective doses. Check an ECG if QT risk factors or other QT-prolonging drugs are present.
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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