Drug interactions
Fluoxetine + Ziprasidone
Severity: Major
Fluoxetine and Ziprasidone: 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
Ziprasidone is associated with clear QT prolongation and fluoxetine may add to this effect, increasing the risk of torsades de pointes. Fluoxetine may also raise ziprasidone exposure slightly through CYP inhibition.
What this interaction means in plain words
Fluoxetine and Ziprasidone 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.
Fluoxetine belongs to Central Nervous System; Ziprasidone belongs to Central Nervous System.
Why it happens
Additive QT prolongation, with possible small pharmacokinetic increase in ziprasidone levels.
What to do
Avoid the combination if an alternative is available, and in any case obtain a baseline ECG and electrolytes. Discontinue ziprasidone if the QTc exceeds about 500 ms.
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 Ziprasidone
- Amiodarone + Ziprasidone Contraindicated
- Amitriptyline + Ziprasidone Contraindicated
- Arsenic trioxide + Ziprasidone Contraindicated
- Bedaquiline + Ziprasidone Contraindicated
- Chloroquine + Ziprasidone Contraindicated
- Citalopram + Ziprasidone Contraindicated
Frequently asked questions
Can I take Fluoxetine with Ziprasidone?
MediHelp rates the interaction as major. Fluoxetine and Ziprasidone 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. Ziprasidone is associated with clear QT prolongation and fluoxetine may add to this effect, increasing the risk of torsades de pointes. Fluoxetine may also raise ziprasidone exposure slightly through CYP inhibition.
How serious is the interaction between Fluoxetine and Ziprasidone?
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 the combination if an alternative is available, and in any case obtain a baseline ECG and electrolytes. Discontinue ziprasidone if the QTc exceeds about 500 ms.
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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