Drug interactions
Levofloxacin + Quizartinib
Severity: Major
Levofloxacin and Quizartinib: 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
Quizartinib markedly prolongs the QT interval and carries a boxed warning for torsades de pointes. Adding levofloxacin, itself a QT-prolonging drug, increases the arrhythmia risk further.
What this interaction means in plain words
Levofloxacin and Quizartinib 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; Quizartinib belongs to Oncology.
Why it happens
Additive prolongation of ventricular repolarisation via cardiac ion channel effects.
What to do
Prefer a non-QT-prolonging antibiotic. If unavoidable, monitor the ECG more frequently, correct electrolytes, and reduce the quizartinib dose where labeling advises.
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 Quizartinib
- Quizartinib + Thioridazine Contraindicated
- Quizartinib + Ziprasidone Contraindicated
- Alfuzosin + Quizartinib Major
- Amiodarone + Quizartinib Major
- Amitriptyline + Quizartinib Major
- Amobarbital + Quizartinib Major
Frequently asked questions
Can I take Levofloxacin with Quizartinib?
MediHelp rates the interaction as major. Levofloxacin and Quizartinib 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. Quizartinib markedly prolongs the QT interval and carries a boxed warning for torsades de pointes. Adding levofloxacin, itself a QT-prolonging drug, increases the arrhythmia risk further.
How serious is the interaction between Levofloxacin and Quizartinib?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer a non-QT-prolonging antibiotic. If unavoidable, monitor the ECG more frequently, correct electrolytes, and reduce the quizartinib dose where labeling advises.
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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