Drug interactions
Quinidine + Valbenazine
Severity: Moderate
Quinidine and Valbenazine: moderate 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, which metabolizes the active metabolite of valbenazine. Exposure to the active metabolite rises, increasing the risk of somnolence and QT prolongation.
What this interaction means in plain words
Quinidine and Valbenazine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Quinidine belongs to Anti Parasitic; Valbenazine belongs to Central Nervous System.
Why it happens
Strong CYP2D6 inhibition by quinidine reduces clearance of valbenazine's active metabolite.
What to do
Consider reducing the valbenazine dose in line with labeling, and monitor for sedation and QTc prolongation.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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 Valbenazine
- Deutetrabenazine + Valbenazine Contraindicated
- Tranylcypromine + Valbenazine Contraindicated
- Amiodarone + Valbenazine Major
- Amisulpride + Valbenazine Major
- Apalutamide + Valbenazine Major
- Carbamazepine + Valbenazine Major
Frequently asked questions
Can I take Quinidine with Valbenazine?
MediHelp rates the interaction as moderate. Quinidine and Valbenazine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Quinidine strongly inhibits CYP2D6, which metabolizes the active metabolite of valbenazine. Exposure to the active metabolite rises, increasing the risk of somnolence and QT prolongation.
How serious is the interaction between Quinidine and Valbenazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Consider reducing the valbenazine dose in line with labeling, and monitor for sedation and QTc prolongation.
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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