Drug interactions
Phenelzine + Valbenazine
Severity: Major
Phenelzine and Valbenazine: 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
Valbenazine is a VMAT2 inhibitor, and MAOIs can raise monoamine levels. This may reduce valbenazine efficacy and has been linked to a theoretical risk of serotonin syndrome.
What this interaction means in plain words
Phenelzine and Valbenazine 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.
Phenelzine belongs to Central Nervous System; Valbenazine belongs to Central Nervous System.
Why it happens
Opposing effects on monoamine handling: VMAT2 inhibition depletes vesicular stores while MAOI increases cytoplasmic monoamines.
What to do
Avoid the combination per labeling. Consider an alternative treatment for tardive dyskinesia, or monitor for lack of effect and serotonin toxicity if both are required.
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 Phenelzine
- 5-HTP + Phenelzine Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amoxapine + Phenelzine Contraindicated
- Atomoxetine + Phenelzine Contraindicated
- Benzphetamine + Phenelzine Contraindicated
- Brimonidine + Phenelzine 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 Phenelzine with Valbenazine?
MediHelp rates the interaction as major. Phenelzine and Valbenazine 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. Valbenazine is a VMAT2 inhibitor, and MAOIs can raise monoamine levels. This may reduce valbenazine efficacy and has been linked to a theoretical risk of serotonin syndrome.
How serious is the interaction between Phenelzine and Valbenazine?
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 per labeling. Consider an alternative treatment for tardive dyskinesia, or monitor for lack of effect and serotonin toxicity if both are required.
What other medicines interact with Phenelzine?
MediHelp also lists interactions of Phenelzine with, for example, 5-HTP, Amitriptyline, Amoxapine. The full list is on the Phenelzine page.
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