Drug interactions
Fluoxetine + Olanzapine / samidorphan
Severity: Moderate
Fluoxetine and Olanzapine / samidorphan: 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
Fluoxetine inhibits CYP2D6 and can modestly raise olanzapine levels, while both agents can cause sedation. Additive CNS effects and orthostatic hypotension may occur.
What this interaction means in plain words
Fluoxetine and Olanzapine / samidorphan 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 CNS depressant and hypotensive effects, with minor pharmacokinetic effects of fluoxetine on olanzapine clearance.
What to do
Monitor sedation and orthostatic blood pressure, especially at initiation and dose changes. Counsel patients about dizziness and falls.
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 Fluoxetine
- Fluoxetine + Isocarboxazid Contraindicated
- Fluoxetine + Mavacamten Contraindicated
- Fluoxetine + Methylene blue Contraindicated
- Fluoxetine + Phenelzine Contraindicated
- Fluoxetine + Pimozide Contraindicated
- Fluoxetine + Rasagiline Contraindicated
Frequently asked questions
Can I take Fluoxetine with Olanzapine / samidorphan?
MediHelp rates the interaction as moderate. Fluoxetine and Olanzapine / samidorphan 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. Fluoxetine inhibits CYP2D6 and can modestly raise olanzapine levels, while both agents can cause sedation. Additive CNS effects and orthostatic hypotension may occur.
How serious is the interaction between Fluoxetine and Olanzapine / samidorphan?
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 and orthostatic blood pressure, especially at initiation and dose changes. Counsel patients about dizziness and falls.
What other medicines interact with Fluoxetine?
MediHelp also lists interactions of Fluoxetine with, for example, Isocarboxazid, Mavacamten, Methylene blue. The full list is on the Fluoxetine page.
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