Drug interactions
Olanzapine + Trifluoperazine
Severity: Moderate
Olanzapine and Trifluoperazine: 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
Using two antipsychotics together raises the burden of dopamine blockade, increasing extrapyramidal symptoms and the risk of neuroleptic malignant syndrome. Sedation, orthostatic hypotension and QT prolongation can also be additive.
What this interaction means in plain words
Olanzapine and Trifluoperazine 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 D2 receptor antagonism plus additive sedative, hypotensive and QT-prolonging effects.
What to do
Avoid antipsychotic polypharmacy where possible; if used, monitor for movement disorders, sedation and ECG changes, and use the lowest effective doses.
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 Olanzapine
Frequently asked questions
Can I take Olanzapine with Trifluoperazine?
MediHelp rates the interaction as moderate. Olanzapine and Trifluoperazine 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. Using two antipsychotics together raises the burden of dopamine blockade, increasing extrapyramidal symptoms and the risk of neuroleptic malignant syndrome. Sedation, orthostatic hypotension and QT prolongation can also be additive.
How serious is the interaction between Olanzapine and Trifluoperazine?
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 used, monitor for movement disorders, sedation and ECG changes, and use the lowest effective doses.
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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