Drug interactions
Donepezil + Olanzapine
Severity: Moderate
Donepezil 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 have been associated with QT prolongation, and donepezil may also cause bradycardia, which further raises the risk of torsades de pointes. Donepezil may also pharmacodynamically oppose the anticholinergic effects of olanzapine, and olanzapine may worsen cognition in dementia.
What this interaction means in plain words
Donepezil 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.
Donepezil belongs to Central Nervous System; Olanzapine belongs to Central Nervous System.
Why it happens
Additive QTc prolongation, with donepezil-induced bradycardia increasing arrhythmia risk.
What to do
Check a baseline ECG and electrolytes in patients with cardiac risk factors and monitor heart rate and QTc. Avoid adding other QT-prolonging drugs.
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 Donepezil
- Donepezil + Dronedarone Contraindicated
- Donepezil + Pimozide Contraindicated
- Donepezil + Thioridazine Contraindicated
- Donepezil + Vandetanib Contraindicated
- Amiodarone + Donepezil Major
- Amisulpride + Donepezil Major
Frequently asked questions
Can I take Donepezil with Olanzapine?
MediHelp rates the interaction as moderate. Donepezil 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 have been associated with QT prolongation, and donepezil may also cause bradycardia, which further raises the risk of torsades de pointes. Donepezil may also pharmacodynamically oppose the anticholinergic effects of olanzapine, and olanzapine may worsen cognition in dementia.
How serious is the interaction between Donepezil 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: Check a baseline ECG and electrolytes in patients with cardiac risk factors and monitor heart rate and QTc. Avoid adding other QT-prolonging drugs.
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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