Drug interactions
Hydroxyzine + Olanzapine
Severity: Moderate
Hydroxyzine and Olanzapine: 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
Both drugs cause sedation, so combined use can increase drowsiness and psychomotor impairment. Hydroxyzine is also associated with QT prolongation and olanzapine has a small potential to do so, so arrhythmia risk may rise, particularly with other risk factors.
What this interaction means in plain words
Hydroxyzine and Olanzapine 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.
Hydroxyzine belongs to Respiratory; Olanzapine belongs to Central Nervous System.
Why it happens
Additive CNS depression via H1 blockade and additive QTc prolongation.
What to do
Use the lowest effective hydroxyzine dose and consider an ECG in patients with cardiac risk factors or electrolyte disturbance. Counsel about sedation and avoid driving until response is known.
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
Other interactions of Hydroxyzine
- Droperidol + Hydroxyzine Contraindicated
- Hydroxyzine + Pimozide Contraindicated
- Hydroxyzine + Thioridazine Contraindicated
- Hydroxyzine + Vandetanib Contraindicated
- Alfentanil + Hydroxyzine Major
- Amiodarone + Hydroxyzine Major
Frequently asked questions
Can I take Hydroxyzine with Olanzapine?
MediHelp rates the interaction as moderate. Hydroxyzine and Olanzapine 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. Both drugs cause sedation, so combined use can increase drowsiness and psychomotor impairment. Hydroxyzine is also associated with QT prolongation and olanzapine has a small potential to do so, so arrhythmia risk may rise, particularly with other risk factors.
How serious is the interaction between Hydroxyzine and Olanzapine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective hydroxyzine dose and consider an ECG in patients with cardiac risk factors or electrolyte disturbance. Counsel about sedation and avoid driving until response is known.
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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