Drug interactions
Baclofen + Promethazine
Severity: Moderate
Baclofen 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 central nervous system depression, so combined use can increase drowsiness, dizziness and impaired coordination. The risk is higher in older or frail patients.
What this interaction means in plain words
Baclofen 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.
Baclofen belongs to Musculoskeletal; Promethazine belongs to Respiratory.
Why it happens
Additive CNS depression via H1 antagonism and GABA-B agonism.
What to do
Start with low doses and monitor sedation and falls risk. Advise avoiding 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 Promethazine
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Other interactions of Baclofen
Frequently asked questions
Can I take Baclofen with Promethazine?
MediHelp rates the interaction as moderate. Baclofen 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 central nervous system depression, so combined use can increase drowsiness, dizziness and impaired coordination. The risk is higher in older or frail patients.
How serious is the interaction between Baclofen 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: Start with low doses and monitor sedation and falls risk. Advise avoiding alcohol and driving.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Promethazine page.
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