Drug interactions
Lurasidone + Thioridazine
Severity: Major
Lurasidone and Thioridazine: major interaction.
Last updated Sources: UK SmPC
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 are antipsychotics, so together they increase the risk of sedation, orthostatic hypotension, extrapyramidal symptoms and neuroleptic malignant syndrome. Thioridazine's strong QT-prolonging effect adds to the cardiac risk of dual antipsychotic therapy. Lurasidone has less QT liability but does not remove the concern.
What this interaction means in plain words
Lurasidone and Thioridazine 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.
Lurasidone belongs to Central Nervous System; Thioridazine belongs to Central Nervous System.
Why it happens
Additive dopamine D2 antagonism, CNS depression and thioridazine-related QT prolongation.
What to do
Avoid combining antipsychotics where possible. If unavoidable, obtain a baseline and follow-up ECG, check electrolytes and monitor for sedation and movement disorders.
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
- Latuda 18.5mg film-coated tablets - SmPC sections 4.3/4.5 (class statement: some other antipsychotics; "Caution is advised when prescribing lurasidone with medicinal products known to prolong the QT interval, e.g. class IA antiarrhythmics (e.g. quinidine, disopyra") — electronic medicines compendium (UK SmPC)
Other interactions of Thioridazine
- Abiraterone + Thioridazine Contraindicated
- Adagrasib + Thioridazine Contraindicated
- Amiodarone + Thioridazine Contraindicated
- Amisulpride + Thioridazine Contraindicated
- Amitriptyline + Thioridazine Contraindicated
- Amoxapine + Thioridazine Contraindicated
Other interactions of Lurasidone
- Apalutamide + Lurasidone Contraindicated
- Atazanavir + Lurasidone Contraindicated
- Carbamazepine + Lurasidone Contraindicated
- Clarithromycin + Lurasidone Contraindicated
- Cobicistat + Lurasidone Contraindicated
- Conivaptan + Lurasidone Contraindicated
Frequently asked questions
Can I take Lurasidone with Thioridazine?
MediHelp rates the interaction as major. Lurasidone and Thioridazine 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 are antipsychotics, so together they increase the risk of sedation, orthostatic hypotension, extrapyramidal symptoms and neuroleptic malignant syndrome. Thioridazine's strong QT-prolonging effect adds to the cardiac risk of dual antipsychotic therapy. Lurasidone has less QT liability but does not remove the concern.
How serious is the interaction between Lurasidone and Thioridazine?
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 combining antipsychotics where possible. If unavoidable, obtain a baseline and follow-up ECG, check electrolytes and monitor for sedation and movement disorders.
What other medicines interact with Thioridazine?
MediHelp also lists interactions of Thioridazine with, for example, Abiraterone, Adagrasib, Amiodarone. The full list is on the Thioridazine page.
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