Drug interactions
fluconazole + 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 may increase risk of torsades de pointes, especially with existing QT risk factors or electrolyte abnormalities.
Mechanism of action
Pharmacodynamic: both agents can block cardiac IKr channels → QT prolongation; fluconazole does not meaningfully alter levofloxacin PK.
Clinical management
Prefer alternatives in high-risk patients. If combined, correct K+/Mg2+, obtain baseline and follow-up ECGs, avoid other QT-prolonging drugs, and adjust levofloxacin for renal function.
Drug reference
References
- Diflucan (fluconazole) Prescribing Information — FDA Label
- Levaquin (levofloxacin) Prescribing Information — FDA Label
- QTdrugs Lists (Fluconazole; Levofloxacin) – Known Risk of Torsades de Pointes — CredibleMeds
Frequently asked questions
Can I take fluconazole with levofloxacin?
The interaction is rated: Moderate. Additive QTc prolongation may increase risk of torsades de pointes, especially with existing QT risk factors or electrolyte abnormalities.
How serious is the interaction between fluconazole and levofloxacin?
The interaction is rated: Moderate. Evidence level: High.
How is the interaction between fluconazole and levofloxacin managed?
Prefer alternatives in high-risk patients. If combined, correct K+/Mg2+, obtain baseline and follow-up ECGs, avoid other QT-prolonging drugs, and adjust levofloxacin for renal function.
Why do fluconazole and levofloxacin interact?
Pharmacodynamic: both agents can block cardiac IKr channels → QT prolongation; fluconazole does not meaningfully alter levofloxacin PK.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.