Drug interactions
Quinidine + Tetrabenazine
Severity: Major
Quinidine and Tetrabenazine: 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 strongly inhibits CYP2D6, increasing active tetrabenazine metabolite exposure, and both drugs can prolong the QT interval. This raises the risk of arrhythmia and tetrabenazine adverse effects such as sedation and parkinsonism.
What this interaction means in plain words
Quinidine and Tetrabenazine 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 belongs to Anti Parasitic; Tetrabenazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation plus quinidine CYP2D6 inhibition raising active tetrabenazine metabolites.
What to do
Avoid if possible. If used, limit the tetrabenazine dose, obtain ECG monitoring and watch for sedation and depression.
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 Tetrabenazine
- Dronedarone + Tetrabenazine Contraindicated
- Isocarboxazid + Tetrabenazine Contraindicated
- Linezolid + Tetrabenazine Contraindicated
- Phenelzine + Tetrabenazine Contraindicated
- Pimozide + Tetrabenazine Contraindicated
- Procarbazine + Tetrabenazine Contraindicated
Frequently asked questions
Can I take Quinidine with Tetrabenazine?
MediHelp rates the interaction as major. Quinidine and Tetrabenazine 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 strongly inhibits CYP2D6, increasing active tetrabenazine metabolite exposure, and both drugs can prolong the QT interval. This raises the risk of arrhythmia and tetrabenazine adverse effects such as sedation and parkinsonism.
How serious is the interaction between Quinidine and Tetrabenazine?
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 used, limit the tetrabenazine dose, obtain ECG monitoring and watch for sedation and depression.
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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