Drug interactions
Nortriptyline + Quinidine
Severity: Major
Nortriptyline and Quinidine: major 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
Quinidine inhibits CYP2D6, increasing nortriptyline concentrations, and both agents slow conduction and prolong QT. This raises the risk of arrhythmia and tricyclic toxicity.
What this interaction means in plain words
Nortriptyline 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.
Nortriptyline belongs to Central Nervous System; Quinidine belongs to Anti Parasitic.
Why it happens
Additive QT and conduction effects with CYP2D6 inhibition by quinidine.
What to do
Avoid if possible. If combined, use a lower nortriptyline dose with plasma level and ECG monitoring.
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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Other interactions of Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Other interactions of Nortriptyline
- Disopyramide + Nortriptyline Contraindicated
- Dofetilide + Nortriptyline Contraindicated
- Dronedarone + Nortriptyline Contraindicated
- Ibutilide + Nortriptyline Contraindicated
- Isocarboxazid + Nortriptyline Contraindicated
- Methylene blue + Nortriptyline Contraindicated
Frequently asked questions
Can I take Nortriptyline with Quinidine?
MediHelp rates the interaction as major. Nortriptyline 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. Quinidine inhibits CYP2D6, increasing nortriptyline concentrations, and both agents slow conduction and prolong QT. This raises the risk of arrhythmia and tricyclic toxicity.
How serious is the interaction between Nortriptyline 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 if possible. If combined, use a lower nortriptyline dose with plasma level and ECG monitoring.
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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