Drug interactions
Chlorpromazine + Primidone
Severity: Moderate
Chlorpromazine and Primidone: 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 depress the central nervous system, so combined use can cause marked drowsiness and impaired psychomotor performance. Primidone, via its phenobarbital metabolite, also induces liver enzymes and may lower chlorpromazine exposure over time.
What this interaction means in plain words
Chlorpromazine and Primidone 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; Primidone belongs to Central Nervous System.
Why it happens
Additive CNS depression, plus CYP enzyme induction by phenobarbital derived from primidone.
What to do
Monitor for oversedation and loss of antipsychotic effect, and adjust chlorpromazine dose as needed. Counsel patients about driving and alcohol.
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 Chlorpromazine
- Chlorpromazine + Dofetilide Contraindicated
- Chlorpromazine + Dronedarone Contraindicated
- Chlorpromazine + Droperidol Contraindicated
- Chlorpromazine + Ibutilide Contraindicated
- Chlorpromazine + Metrizamide Contraindicated
- Chlorpromazine + Panobinostat Contraindicated
Other interactions of Primidone
- Lorlatinib + Primidone Contraindicated
- Lurasidone + Primidone Contraindicated
- Primidone + Ranolazine Contraindicated
- Primidone + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Primidone + Voriconazole Contraindicated
- Abiraterone + Primidone Major
Frequently asked questions
Can I take Chlorpromazine with Primidone?
MediHelp rates the interaction as moderate. Chlorpromazine and Primidone 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 depress the central nervous system, so combined use can cause marked drowsiness and impaired psychomotor performance. Primidone, via its phenobarbital metabolite, also induces liver enzymes and may lower chlorpromazine exposure over time.
How serious is the interaction between Chlorpromazine and Primidone?
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 loss of antipsychotic effect, and adjust chlorpromazine dose as needed. Counsel patients about driving and alcohol.
What other medicines interact with Chlorpromazine?
MediHelp also lists interactions of Chlorpromazine with, for example, Dofetilide, Dronedarone, Droperidol. The full list is on the Chlorpromazine page.
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