Drug interactions
Fluoxetine + Posaconazole
Severity: Moderate
Fluoxetine and Posaconazole: 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 agents can prolong the QT interval, so giving them together may raise the risk of torsades de pointes, particularly in patients with electrolyte disturbances, bradycardia or structural heart disease. Fluoxetine is also a CYP2D6 and CYP2C19 inhibitor, but the main concern here is additive cardiac repolarization effects.
What this interaction means in plain words
Fluoxetine and Posaconazole 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; Posaconazole belongs to Anti Fungals.
Why it happens
Additive pharmacodynamic QT prolongation through effects on cardiac repolarization.
What to do
Obtain a baseline ECG and correct potassium and magnesium before starting, then repeat the ECG during co-therapy. Consider an alternative antidepressant if QTc becomes markedly prolonged or the patient has other risk factors.
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 Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
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 Posaconazole?
MediHelp rates the interaction as moderate. Fluoxetine and Posaconazole 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 agents can prolong the QT interval, so giving them together may raise the risk of torsades de pointes, particularly in patients with electrolyte disturbances, bradycardia or structural heart disease. Fluoxetine is also a CYP2D6 and CYP2C19 inhibitor, but the main concern here is additive cardiac repolarization effects.
How serious is the interaction between Fluoxetine and Posaconazole?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and correct potassium and magnesium before starting, then repeat the ECG during co-therapy. Consider an alternative antidepressant if QTc becomes markedly prolonged or the patient has other risk factors.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole page.
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