Drug interactions
Fluoxetine + Ibutilide
Severity: Major
Fluoxetine and Ibutilide: 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
Ibutilide markedly prolongs repolarization and carries a substantial risk of torsades de pointes. Fluoxetine adds some QT-prolonging effect, which could increase that risk further.
What this interaction means in plain words
Fluoxetine and Ibutilide 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; Ibutilide belongs to Cardiovascular.
Why it happens
Additive prolongation of ventricular repolarization via potassium channel blockade.
What to do
Avoid giving ibutilide to patients taking fluoxetine where possible. If cardioversion with ibutilide is needed, correct electrolytes and monitor the ECG continuously during and after the infusion.
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 Ibutilide
- Amiodarone + Ibutilide Contraindicated
- Amisulpride + Ibutilide Contraindicated
- Chlorpromazine + Ibutilide Contraindicated
- Clarithromycin + Ibutilide Contraindicated
- Desipramine + Ibutilide Contraindicated
- Dolasetron + Ibutilide Contraindicated
Frequently asked questions
Can I take Fluoxetine with Ibutilide?
MediHelp rates the interaction as major. Fluoxetine and Ibutilide 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. Ibutilide markedly prolongs repolarization and carries a substantial risk of torsades de pointes. Fluoxetine adds some QT-prolonging effect, which could increase that risk further.
How serious is the interaction between Fluoxetine and Ibutilide?
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 giving ibutilide to patients taking fluoxetine where possible. If cardioversion with ibutilide is needed, correct electrolytes and monitor the ECG continuously during and after the infusion.
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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