Drug interactions
Ketoconazole + Levofloxacin
Severity: Moderate
Ketoconazole and Levofloxacin: 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 have been associated with QT prolongation, so combined use may increase the risk of torsades de pointes. The overall risk is greatest in patients with other QT risk factors.
What this interaction means in plain words
Ketoconazole and Levofloxacin 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.
Ketoconazole belongs to Anti Fungals; Levofloxacin belongs to Anti Bacterial.
Why it happens
Additive blockade of cardiac potassium channels prolonging ventricular repolarization.
What to do
Obtain a baseline ECG in at-risk patients, correct potassium and magnesium, and monitor the QTc. Consider alternatives if other QT-prolonging drugs are present.
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 Levofloxacin
- Dronedarone + Levofloxacin Contraindicated
- Ibutilide + Levofloxacin Contraindicated
- Levofloxacin + Thioridazine Contraindicated
- Levofloxacin + Vandetanib Contraindicated
- Levofloxacin + Ziprasidone Contraindicated
- Adagrasib + Levofloxacin Major
Other interactions of Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Frequently asked questions
Can I take Ketoconazole with Levofloxacin?
MediHelp rates the interaction as moderate. Ketoconazole and Levofloxacin 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 have been associated with QT prolongation, so combined use may increase the risk of torsades de pointes. The overall risk is greatest in patients with other QT risk factors.
How serious is the interaction between Ketoconazole and Levofloxacin?
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 in at-risk patients, correct potassium and magnesium, and monitor the QTc. Consider alternatives if other QT-prolonging drugs are present.
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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