Drug interactions
Azithromycin + Posaconazole
Severity: Moderate
Azithromycin 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 drugs can prolong the QT interval, and their combination may increase the risk of torsades de pointes. Risk is higher in patients with electrolyte disturbances, bradycardia or structural heart disease.
What this interaction means in plain words
Azithromycin 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.
Azithromycin belongs to Anti Bacterial; Posaconazole belongs to Anti Fungals.
Why it happens
Additive QTc prolongation through hERG potassium channel inhibition.
What to do
Obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc during combined use. Consider an alternative antibiotic in patients with prolonged QTc.
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 Azithromycin
- Azithromycin + Cisapride Contraindicated
- Azithromycin + Domperidone Contraindicated
- Azithromycin + Dronedarone Contraindicated
- Azithromycin + Pimozide Contraindicated
- Azithromycin + Piperaquine Contraindicated
- Azithromycin + Thioridazine Contraindicated
Other interactions of Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
Frequently asked questions
Can I take Azithromycin with Posaconazole?
MediHelp rates the interaction as moderate. Azithromycin 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 drugs can prolong the QT interval, and their combination may increase the risk of torsades de pointes. Risk is higher in patients with electrolyte disturbances, bradycardia or structural heart disease.
How serious is the interaction between Azithromycin 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, correct potassium and magnesium, and monitor the QTc during combined use. Consider an alternative antibiotic in patients with prolonged QTc.
What other medicines interact with Azithromycin?
MediHelp also lists interactions of Azithromycin with, for example, Cisapride, Domperidone, Dronedarone. The full list is on the Azithromycin page.
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