Drug interactions
Perphenazine + Valbenazine
Severity: Moderate
Perphenazine 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
Valbenazine can prolong the QT interval at higher exposures and perphenazine also carries QT risk, so the combination may increase arrhythmia risk. Perphenazine is a CYP2D6 substrate, and valbenazine's active metabolite may affect CYP2D6 handling only modestly.
What this interaction means in plain words
Perphenazine 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.
Perphenazine belongs to Central Nervous System; Valbenazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation.
What to do
Consider a baseline ECG and monitor electrolytes and QTc, especially in patients with cardiac risk factors or CYP2D6 poor metabolizer status.
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 Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
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 Perphenazine with Valbenazine?
MediHelp rates the interaction as moderate. Perphenazine 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. Valbenazine can prolong the QT interval at higher exposures and perphenazine also carries QT risk, so the combination may increase arrhythmia risk. Perphenazine is a CYP2D6 substrate, and valbenazine's active metabolite may affect CYP2D6 handling only modestly.
How serious is the interaction between Perphenazine 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 a baseline ECG and monitor electrolytes and QTc, especially in patients with cardiac risk factors or CYP2D6 poor metabolizer status.
What other medicines interact with Perphenazine?
MediHelp also lists interactions of Perphenazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Perphenazine page.
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