Drug interactions
Chlorpromazine + Flecainide
Severity: Major
Chlorpromazine and Flecainide: 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 can prolong the QT interval, and combined use increases the risk of torsades de pointes and conduction disturbances. Chlorpromazine also inhibits CYP2D6 and may raise flecainide levels.
What this interaction means in plain words
Chlorpromazine and Flecainide 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; Flecainide belongs to Cardiovascular.
Why it happens
Additive QT prolongation and conduction slowing, with CYP2D6 inhibition by chlorpromazine.
What to do
Avoid the combination where possible; otherwise monitor ECG, electrolytes and flecainide levels.
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 Flecainide
- Flecainide + Nirmatrelvir Contraindicated
- Flecainide + Nirmatrelvir / ritonavir Contraindicated
- Flecainide + Pimozide Contraindicated
- Flecainide + Ritonavir Contraindicated
- Flecainide + Thioridazine Contraindicated
- Flecainide + Tipranavir 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 Flecainide?
MediHelp rates the interaction as major. Chlorpromazine and Flecainide 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 can prolong the QT interval, and combined use increases the risk of torsades de pointes and conduction disturbances. Chlorpromazine also inhibits CYP2D6 and may raise flecainide levels.
How serious is the interaction between Chlorpromazine and Flecainide?
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 the combination where possible; otherwise monitor ECG, electrolytes and flecainide levels.
What other medicines interact with Flecainide?
MediHelp also lists interactions of Flecainide with, for example, Nirmatrelvir, Nirmatrelvir / ritonavir, Pimozide. The full list is on the Flecainide page.
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