Drug interactions
Chlorpromazine + Fluoxetine
Severity: Moderate
Chlorpromazine and Fluoxetine: 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
Fluoxetine inhibits CYP2D6, which contributes to chlorpromazine metabolism, and may raise chlorpromazine levels. Chlorpromazine can also prolong the QT interval, and higher exposure may cause more sedation, hypotension and extrapyramidal effects.
What this interaction means in plain words
Chlorpromazine and Fluoxetine 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; Fluoxetine belongs to Central Nervous System.
Why it happens
CYP2D6 inhibition by fluoxetine reduces chlorpromazine clearance, with possible additive QT effects.
What to do
Monitor for excessive sedation, hypotension and extrapyramidal symptoms and consider lowering the chlorpromazine dose. Obtain an ECG in patients with cardiac risk factors or other QT-prolonging drugs.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Chlorpromazine and Fluoxetine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Fluoxetine
- Fluoxetine + Isocarboxazid Contraindicated
- Fluoxetine + Mavacamten Contraindicated
- Fluoxetine + Methylene blue Contraindicated
- Fluoxetine + Phenelzine Contraindicated
- Fluoxetine + Pimozide Contraindicated
- Fluoxetine + Rasagiline Contraindicated
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 Fluoxetine?
MediHelp rates the interaction as moderate. Chlorpromazine and Fluoxetine 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. Fluoxetine inhibits CYP2D6, which contributes to chlorpromazine metabolism, and may raise chlorpromazine levels. Chlorpromazine can also prolong the QT interval, and higher exposure may cause more sedation, hypotension and extrapyramidal effects.
How serious is the interaction between Chlorpromazine and Fluoxetine?
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 excessive sedation, hypotension and extrapyramidal symptoms and consider lowering the chlorpromazine dose. Obtain an ECG in patients with cardiac risk factors or other QT-prolonging drugs.
What other medicines interact with Fluoxetine?
MediHelp also lists interactions of Fluoxetine with, for example, Isocarboxazid, Mavacamten, Methylene blue. The full list is on the Fluoxetine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
