Drug interactions
Clozapine + Tetrabenazine
Severity: Major
Clozapine 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
Both drugs can prolong the QT interval, so combined use increases the risk of torsades de pointes. Tetrabenazine can also cause sedation, parkinsonism and neuroleptic malignant syndrome, which may add to the effects of clozapine.
What this interaction means in plain words
Clozapine 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.
Clozapine belongs to Central Nervous System; Tetrabenazine belongs to Central Nervous System.
Why it happens
Additive QTc prolongation, with overlapping CNS depressant and dopamine-depleting effects.
What to do
Obtain a baseline ECG and monitor QTc and electrolytes. Use the lowest effective doses and watch for sedation and neuroleptic malignant syndrome.
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 Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
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 Clozapine with Tetrabenazine?
MediHelp rates the interaction as major. Clozapine 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. Both drugs can prolong the QT interval, so combined use increases the risk of torsades de pointes. Tetrabenazine can also cause sedation, parkinsonism and neuroleptic malignant syndrome, which may add to the effects of clozapine.
How serious is the interaction between Clozapine 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: Obtain a baseline ECG and monitor QTc and electrolytes. Use the lowest effective doses and watch for sedation and neuroleptic malignant syndrome.
What other medicines interact with Clozapine?
MediHelp also lists interactions of Clozapine with, for example, Deferiprone, Irinotecan, Pimozide. The full list is on the Clozapine page.
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