Drug interactions
Escitalopram + Fluoxetine
Severity: Major
Escitalopram and Fluoxetine: major interaction.
Last updated Sources: US FDA label
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 are SSRIs, so combined use adds serotonergic effect and increases the risk of serotonin syndrome. Fluoxetine also inhibits CYP2C19 and CYP2D6 and may raise escitalopram concentrations, adding to dose-related QT prolongation.
What this interaction means in plain words
Escitalopram and Fluoxetine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Escitalopram belongs to Central Nervous System; Fluoxetine belongs to Central Nervous System.
Why it happens
Additive serotonin reuptake inhibition plus fluoxetine inhibition of CYP2C19 and CYP2D6 metabolism of escitalopram.
What to do
Avoid concurrent use of two SSRIs; choose one agent and cross-taper carefully, accounting for the prolonged fluoxetine washout. If overlap is unavoidable, monitor for serotonin toxicity and consider ECG.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Fluoxetine
- Fluoxetine + Isocarboxazid Contraindicated
- Fluoxetine + Mavacamten Contraindicated
- Fluoxetine + Methylene blue Contraindicated
- Fluoxetine + Phenelzine Contraindicated
- Fluoxetine + Pimozide Contraindicated
- Fluoxetine + Rasagiline Contraindicated
Other interactions of Escitalopram
- Cisapride + Escitalopram Contraindicated
- Citalopram + Escitalopram Contraindicated
- Escitalopram + Isocarboxazid Contraindicated
- Escitalopram + Methylene blue Contraindicated
- Escitalopram + Phenelzine Contraindicated
- Escitalopram + Pimozide Contraindicated
Frequently asked questions
Can I take Escitalopram with Fluoxetine?
MediHelp rates the interaction as major. Escitalopram and Fluoxetine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both are SSRIs, so combined use adds serotonergic effect and increases the risk of serotonin syndrome. Fluoxetine also inhibits CYP2C19 and CYP2D6 and may raise escitalopram concentrations, adding to dose-related QT prolongation.
How serious is the interaction between Escitalopram and Fluoxetine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use of two SSRIs; choose one agent and cross-taper carefully, accounting for the prolonged fluoxetine washout. If overlap is unavoidable, monitor for serotonin toxicity and consider ECG.
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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