Drug interactions
Quetiapine + Thiothixene
Severity: Moderate
Quetiapine and Thiothixene: moderate 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
Combining two antipsychotics increases the risk of sedation, extrapyramidal symptoms, neuroleptic malignant syndrome and QT prolongation. Thiothixene is a high-potency agent with substantial dopamine blockade, so the additive burden can be clinically relevant.
What this interaction means in plain words
Quetiapine and Thiothixene can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Additive dopamine D2 blockade, CNS depression and QT prolongation.
What to do
Avoid antipsychotic polypharmacy where possible. If both are used, obtain a baseline ECG and monitor for extrapyramidal symptoms, sedation and fever or rigidity.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Quetiapine
- Adagrasib + Quetiapine Major
- Amiodarone + Quetiapine Major
- Amisulpride + Quetiapine Major
- Amoxapine + Quetiapine Major
- Anagrelide + Quetiapine Major
- Apalutamide + Quetiapine Major
Frequently asked questions
Can I take Quetiapine with Thiothixene?
MediHelp rates the interaction as moderate. Quetiapine and Thiothixene can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Combining two antipsychotics increases the risk of sedation, extrapyramidal symptoms, neuroleptic malignant syndrome and QT prolongation. Thiothixene is a high-potency agent with substantial dopamine blockade, so the additive burden can be clinically relevant.
How serious is the interaction between Quetiapine and Thiothixene?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid antipsychotic polypharmacy where possible. If both are used, obtain a baseline ECG and monitor for extrapyramidal symptoms, sedation and fever or rigidity.
What other medicines interact with Quetiapine?
MediHelp also lists interactions of Quetiapine with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Quetiapine page.
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