Drug interactions
Olanzapine + Tetrabenazine
Severity: Major
Olanzapine 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
Tetrabenazine prolongs the QT interval and olanzapine may add to this. Both drugs can also cause extrapyramidal symptoms, sedation and, rarely, neuroleptic malignant syndrome.
What this interaction means in plain words
Olanzapine 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.
Olanzapine belongs to Central Nervous System; Tetrabenazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation, plus additive dopaminergic blockade or depletion.
What to do
Obtain a baseline ECG and monitor the QTc, especially at higher tetrabenazine doses. Monitor for parkinsonism, sedation, depression and rigidity or fever.
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 Olanzapine
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 Olanzapine with Tetrabenazine?
MediHelp rates the interaction as major. Olanzapine 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. Tetrabenazine prolongs the QT interval and olanzapine may add to this. Both drugs can also cause extrapyramidal symptoms, sedation and, rarely, neuroleptic malignant syndrome.
How serious is the interaction between Olanzapine 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 the QTc, especially at higher tetrabenazine doses. Monitor for parkinsonism, sedation, depression and rigidity or fever.
What other medicines interact with Olanzapine?
MediHelp also lists interactions of Olanzapine with, for example, Amisulpride, Amoxapine, Apomorphine. The full list is on the Olanzapine page.
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