Drug interactions
hydroxychloroquine + levofloxacin
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.
Overview
Additive QTc prolongation increases risk of torsades de pointes and ventricular arrhythmias, especially with baseline QT prolongation, electrolyte abnormalities, bradycardia, or structural heart disease.
Mechanism of action
Pharmacodynamic additive blockade of cardiac IKr (hERG) channels leading to QT prolongation.
Clinical management
Avoid combination if possible; choose a non–QT-prolonging alternative. If necessary, obtain baseline and follow-up ECG, correct K/Mg, avoid other QT-prolonging drugs, and monitor for palpitations/syncope.
Drug reference
References
- Levofloxacin Prescribing Information — FDA Label
- Plaquenil (hydroxychloroquine sulfate) Prescribing Information — FDA Label
- QTdrugs Lists: Levofloxacin; Hydroxychloroquine — CredibleMeds
Frequently asked questions
Can I take hydroxychloroquine with levofloxacin?
The interaction is rated: Major. Additive QTc prolongation increases risk of torsades de pointes and ventricular arrhythmias, especially with baseline QT prolongation, electrolyte abnormalities, bradycardia, or structural heart disease.
How serious is the interaction between hydroxychloroquine and levofloxacin?
The interaction is rated: Major. Evidence level: High.
How is the interaction between hydroxychloroquine and levofloxacin managed?
Avoid combination if possible; choose a non–QT-prolonging alternative. If necessary, obtain baseline and follow-up ECG, correct K/Mg, avoid other QT-prolonging drugs, and monitor for palpitations/syncope.
Why do hydroxychloroquine and levofloxacin interact?
Pharmacodynamic additive blockade of cardiac IKr (hERG) channels leading to QT prolongation.
Full monographs, dosing and an interaction checker in the MediHelp app
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