Drug interactions
Fluoxetine + Primaquine
Severity: Moderate
Fluoxetine and Primaquine: 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
Both drugs may prolong the QT interval, so combining them may increase the risk of torsades de pointes. Fluoxetine's long half-life means the effect persists after it is stopped.
What this interaction means in plain words
Fluoxetine and Primaquine 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 belongs to Central Nervous System; Primaquine belongs to Anti Parasitic.
Why it happens
Additive QTc prolongation; fluoxetine also inhibits CYP2D6, though its effect on primaquine is unclear.
What to do
Check a baseline ECG and electrolytes, then monitor the ECG during primaquine therapy. Seek alternatives if the QTc is markedly prolonged.
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 Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
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 Primaquine?
MediHelp rates the interaction as moderate. Fluoxetine and Primaquine 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. Both drugs may prolong the QT interval, so combining them may increase the risk of torsades de pointes. Fluoxetine's long half-life means the effect persists after it is stopped.
How serious is the interaction between Fluoxetine and Primaquine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check a baseline ECG and electrolytes, then monitor the ECG during primaquine therapy. Seek alternatives if the QTc is markedly prolonged.
What other medicines interact with Primaquine?
MediHelp also lists interactions of Primaquine with, for example, Pimozide, Amiodarone, Amisulpride. The full list is on the Primaquine page.
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