Drug interactions
Chlorpromazine + Diazepam
Severity: Moderate
Chlorpromazine and Diazepam: 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
Chlorpromazine is strongly sedating and can lower blood pressure, so together with diazepam it may cause marked sedation, hypotension and respiratory depression. Elderly or debilitated patients are especially vulnerable.
What this interaction means in plain words
Chlorpromazine and Diazepam 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.
Chlorpromazine belongs to Central Nervous System; Diazepam belongs to Musculoskeletal.
Why it happens
Additive CNS depression and hypotension from GABA-A potentiation plus antagonism of histamine, alpha-adrenergic and dopamine receptors.
What to do
Use the lowest effective doses and monitor sedation, blood pressure and respiratory status. Titrate slowly and warn about orthostatic dizziness.
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 Diazepam
Other interactions of Chlorpromazine
- Chlorpromazine + Dofetilide Contraindicated
- Chlorpromazine + Dronedarone Contraindicated
- Chlorpromazine + Droperidol Contraindicated
- Chlorpromazine + Ibutilide Contraindicated
- Chlorpromazine + Metrizamide Contraindicated
- Chlorpromazine + Panobinostat Contraindicated
Frequently asked questions
Can I take Chlorpromazine with Diazepam?
MediHelp rates the interaction as moderate. Chlorpromazine and Diazepam 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. Chlorpromazine is strongly sedating and can lower blood pressure, so together with diazepam it may cause marked sedation, hypotension and respiratory depression. Elderly or debilitated patients are especially vulnerable.
How serious is the interaction between Chlorpromazine and Diazepam?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective doses and monitor sedation, blood pressure and respiratory status. Titrate slowly and warn about orthostatic dizziness.
What other medicines interact with Diazepam?
MediHelp also lists interactions of Diazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Alfentanil, Alprazolam. The full list is on the Diazepam page.
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