Drug interactions
Chlorpromazine + Olanzapine
Severity: Moderate
Chlorpromazine and Olanzapine: 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 antipsychotics can affect cardiac repolarization, although olanzapine has a relatively small QT effect. Combined use adds sedation, anticholinergic effects, hypotension and metabolic burden, and may modestly increase arrhythmia risk.
What this interaction means in plain words
Chlorpromazine and Olanzapine 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; Olanzapine belongs to Central Nervous System.
Why it happens
Additive D2, muscarinic, histaminic and alpha-adrenergic blockade, with additive effects on cardiac repolarization.
What to do
Avoid routine antipsychotic combinations; if used, monitor ECG, sedation, orthostatic blood pressure and metabolic parameters.
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 Olanzapine
Frequently asked questions
Can I take Chlorpromazine with Olanzapine?
MediHelp rates the interaction as moderate. Chlorpromazine and Olanzapine 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 antipsychotics can affect cardiac repolarization, although olanzapine has a relatively small QT effect. Combined use adds sedation, anticholinergic effects, hypotension and metabolic burden, and may modestly increase arrhythmia risk.
How serious is the interaction between Chlorpromazine and Olanzapine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid routine antipsychotic combinations; if used, monitor ECG, sedation, orthostatic blood pressure and metabolic parameters.
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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