Drug interactions
Amoxapine + Chlorpromazine
Severity: Major
Amoxapine and Chlorpromazine: major interaction.
Last updated Sources: US FDA label
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, so using them together raises the chance of torsades de pointes and other serious ventricular arrhythmias. Both also have anticholinergic and sedative effects that may add together.
What this interaction means in plain words
Amoxapine and Chlorpromazine 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.
Why it happens
Additive blockade of cardiac hERG potassium channels causing delayed repolarization, plus overlapping anticholinergic and sedative effects.
What to do
Avoid the combination where possible and choose an agent with less QT effect. If it is unavoidable, obtain a baseline and follow-up ECG and correct potassium and magnesium.
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
Frequently asked questions
Can I take Amoxapine with Chlorpromazine?
MediHelp rates the interaction as major. Amoxapine and Chlorpromazine 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, so using them together raises the chance of torsades de pointes and other serious ventricular arrhythmias. Both also have anticholinergic and sedative effects that may add together.
How serious is the interaction between Amoxapine and Chlorpromazine?
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 and choose an agent with less QT effect. If it is unavoidable, obtain a baseline and follow-up ECG and correct potassium and magnesium.
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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