Drug interactions
Amoxapine + Quinidine
Severity: Major
Amoxapine and Quinidine: 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 agents can prolong the QTc interval, and combined use raises the risk of torsades de pointes. Quinidine also inhibits CYP2D6 and may raise amoxapine levels.
What this interaction means in plain words
Amoxapine and Quinidine 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 QT prolongation, with CYP2D6 inhibition by quinidine increasing amoxapine exposure.
What to do
Avoid the combination; choose an alternative antidepressant, or monitor ECG and electrolytes if unavoidable.
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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Frequently asked questions
Can I take Amoxapine with Quinidine?
MediHelp rates the interaction as major. Amoxapine and Quinidine 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 agents can prolong the QTc interval, and combined use raises the risk of torsades de pointes. Quinidine also inhibits CYP2D6 and may raise amoxapine levels.
How serious is the interaction between Amoxapine and Quinidine?
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; choose an alternative antidepressant, or monitor ECG and electrolytes if unavoidable.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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