Drug interactions
Chlorpromazine + Quetiapine
Severity: Major
Chlorpromazine and Quetiapine: major interaction.
Last updated Sources: UK SmPC
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 antipsychotics that can prolong the QT interval, so combined use raises the risk of arrhythmia, hypotension, sedation and extrapyramidal symptoms. Neuroleptic malignant syndrome risk is also additive.
What this interaction means in plain words
Chlorpromazine and Quetiapine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Chlorpromazine belongs to Central Nervous System; Quetiapine belongs to Central Nervous System.
Why it happens
Additive QT prolongation, dopamine D2 antagonism, and antihistaminic and alpha-blocking sedation.
What to do
Avoid antipsychotic combinations where possible; if needed, check ECG and electrolytes and monitor for sedation, orthostasis and movement disorders.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
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 Quetiapine
- Adagrasib + Quetiapine Major
- Amiodarone + Quetiapine Major
- Amisulpride + Quetiapine Major
- Amoxapine + Quetiapine Major
- Anagrelide + Quetiapine Major
- Apalutamide + Quetiapine Major
Frequently asked questions
Can I take Chlorpromazine with Quetiapine?
MediHelp rates the interaction as major. Chlorpromazine and Quetiapine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both drugs are sedating antipsychotics that can prolong the QT interval, so combined use raises the risk of arrhythmia, hypotension, sedation and extrapyramidal symptoms. Neuroleptic malignant syndrome risk is also additive.
How serious is the interaction between Chlorpromazine and Quetiapine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid antipsychotic combinations where possible; if needed, check ECG and electrolytes and monitor for sedation, orthostasis and movement disorders.
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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