Drug interactions
Chlorzoxazone + Promethazine
Severity: Moderate
Chlorzoxazone and Promethazine: 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 cause drowsiness, so combined use can increase sedation, dizziness and impaired psychomotor performance.
What this interaction means in plain words
Chlorzoxazone and Promethazine 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.
Chlorzoxazone belongs to Musculoskeletal; Promethazine belongs to Respiratory.
Why it happens
Additive central nervous system depression.
What to do
Monitor for excessive sedation and advise caution with driving. Reduce doses if drowsiness is significant.
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 Promethazine
- Cabergoline + Promethazine Contraindicated
- Dopamine + Promethazine Contraindicated
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
Other interactions of Chlorzoxazone
Frequently asked questions
Can I take Chlorzoxazone with Promethazine?
MediHelp rates the interaction as moderate. Chlorzoxazone and Promethazine 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 cause drowsiness, so combined use can increase sedation, dizziness and impaired psychomotor performance.
How serious is the interaction between Chlorzoxazone and Promethazine?
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 excessive sedation and advise caution with driving. Reduce doses if drowsiness is significant.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Cabergoline, Dopamine, Ibutilide. The full list is on the Promethazine page.
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