Drug interactions
Levofloxacin + Posaconazole
Severity: Major
Levofloxacin and Posaconazole: major 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 combining them raises the risk of torsades de pointes. Posaconazole is a well-recognized QT-prolonging azole, so risk is higher with electrolyte disturbances or cardiac disease.
What this interaction means in plain words
Levofloxacin and Posaconazole 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.
Levofloxacin belongs to Anti Bacterial; Posaconazole belongs to Anti Fungals.
Why it happens
Additive hERG potassium channel blockade producing delayed ventricular repolarization.
What to do
Avoid the combination where an alternative exists; otherwise correct electrolytes, obtain a baseline ECG and monitor the QTc throughout.
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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Other interactions of Levofloxacin
- Dronedarone + Levofloxacin Contraindicated
- Ibutilide + Levofloxacin Contraindicated
- Levofloxacin + Thioridazine Contraindicated
- Levofloxacin + Vandetanib Contraindicated
- Levofloxacin + Ziprasidone Contraindicated
- Adagrasib + Levofloxacin Major
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 Levofloxacin with Posaconazole?
MediHelp rates the interaction as major. Levofloxacin and Posaconazole 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. Both drugs can prolong the QT interval, and combining them raises the risk of torsades de pointes. Posaconazole is a well-recognized QT-prolonging azole, so risk is higher with electrolyte disturbances or cardiac disease.
How serious is the interaction between Levofloxacin and Posaconazole?
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 the combination where an alternative exists; otherwise correct electrolytes, obtain a baseline ECG and monitor the QTc throughout.
What other medicines interact with Levofloxacin?
MediHelp also lists interactions of Levofloxacin with, for example, Dronedarone, Ibutilide, Thioridazine. The full list is on the Levofloxacin page.
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