Drug interactions
Fluoxetine + Pentamidine
Severity: Major
Fluoxetine and Pentamidine: 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
Pentamidine, particularly intravenously, can prolong the QT interval and cause torsades de pointes. Fluoxetine adds some QT liability, increasing the risk of arrhythmia.
What this interaction means in plain words
Fluoxetine and Pentamidine 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; Pentamidine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation.
What to do
Avoid systemic pentamidine with fluoxetine where possible. If it is necessary, monitor ECG, potassium, magnesium and glucose.
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 Pentamidine
- Clomipramine + Pentamidine Contraindicated
- Desipramine + Pentamidine Contraindicated
- Dronedarone + Pentamidine Contraindicated
- Moxifloxacin + Pentamidine Contraindicated
- Nortriptyline + Pentamidine Contraindicated
- Pentamidine + Pimozide Contraindicated
Frequently asked questions
Can I take Fluoxetine with Pentamidine?
MediHelp rates the interaction as major. Fluoxetine and Pentamidine 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. Pentamidine, particularly intravenously, can prolong the QT interval and cause torsades de pointes. Fluoxetine adds some QT liability, increasing the risk of arrhythmia.
How serious is the interaction between Fluoxetine and Pentamidine?
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 systemic pentamidine with fluoxetine where possible. If it is necessary, monitor ECG, potassium, magnesium and glucose.
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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