Drug interactions
Amitriptyline + Olanzapine
Severity: Moderate
Amitriptyline 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, anticholinergic effects and weight gain, and both may modestly prolong the QT interval. Combined use increases risk of drowsiness, constipation, urinary retention, confusion and arrhythmia, particularly in older patients.
What this interaction means in plain words
Amitriptyline 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.
Amitriptyline belongs to Central Nervous System; Olanzapine belongs to Central Nervous System.
Why it happens
Additive H1, muscarinic and alpha-1 blockade, and additive QT prolongation.
What to do
Monitor sedation, anticholinergic effects, metabolic parameters and ECG in patients with cardiac risk factors. Use the lowest effective doses and correct electrolyte abnormalities.
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 Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Other interactions of Olanzapine
Frequently asked questions
Can I take Amitriptyline with Olanzapine?
MediHelp rates the interaction as moderate. Amitriptyline 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, anticholinergic effects and weight gain, and both may modestly prolong the QT interval. Combined use increases risk of drowsiness, constipation, urinary retention, confusion and arrhythmia, particularly in older patients.
How serious is the interaction between Amitriptyline 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: Monitor sedation, anticholinergic effects, metabolic parameters and ECG in patients with cardiac risk factors. Use the lowest effective doses and correct electrolyte abnormalities.
What other medicines interact with Amitriptyline?
MediHelp also lists interactions of Amitriptyline with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Amitriptyline page.
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