Drug interactions
Loxapine + Tetrabenazine
Severity: Major
Loxapine and Tetrabenazine: major interaction.
Last updated Sources: US FDA label
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 reduce dopaminergic transmission, so combined use can increase parkinsonism, akathisia, dystonia and the risk of neuroleptic malignant syndrome. Tetrabenazine also prolongs the QT interval, and depression is a concern with it.
What this interaction means in plain words
Loxapine 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.
Loxapine belongs to Central Nervous System; Tetrabenazine belongs to Central Nervous System.
Why it happens
Additive dopamine depletion by VMAT2 inhibition (tetrabenazine) and dopamine D2 receptor blockade (loxapine).
What to do
Avoid the combination when possible; if it is needed, use the lowest doses and monitor for extrapyramidal symptoms, rigidity, fever and mood changes. Stop both drugs and treat urgently if neuroleptic malignant syndrome is suspected.
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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References
Other interactions of Loxapine
- Alfentanil + Loxapine Major
- Alprazolam + Loxapine Major
- Amisulpride + Loxapine Major
- Amoxapine + Loxapine Major
- Apomorphine + Loxapine Major
- Belladonna and opium + Loxapine 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 Loxapine with Tetrabenazine?
MediHelp rates the interaction as major. Loxapine 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 reduce dopaminergic transmission, so combined use can increase parkinsonism, akathisia, dystonia and the risk of neuroleptic malignant syndrome. Tetrabenazine also prolongs the QT interval, and depression is a concern with it.
How serious is the interaction between Loxapine 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: Avoid the combination when possible; if it is needed, use the lowest doses and monitor for extrapyramidal symptoms, rigidity, fever and mood changes. Stop both drugs and treat urgently if neuroleptic malignant syndrome is suspected.
What other medicines interact with Loxapine?
MediHelp also lists interactions of Loxapine with, for example, Alfentanil, Alprazolam, Amisulpride. The full list is on the Loxapine page.
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