Drug interactions
Ketoconazole + Ofloxacin
Severity: Major
Ketoconazole and Ofloxacin: 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 combined use increases the risk of torsades de pointes. Ketoconazole is also hepatotoxic, which is relevant given fluoroquinolone liver effects.
What this interaction means in plain words
Ketoconazole and Ofloxacin 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.
Ketoconazole belongs to Anti Fungals; Ofloxacin belongs to Anti Bacterial.
Why it happens
Additive QT prolongation through cardiac potassium channel blockade.
What to do
Avoid if possible; otherwise obtain baseline ECG, correct potassium and magnesium, and monitor the QTc and liver tests.
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 Ofloxacin
- Ofloxacin + Thioridazine Contraindicated
- Adagrasib + Ofloxacin Major
- Amiodarone + Ofloxacin Major
- Amisulpride + Ofloxacin Major
- Anagrelide + Ofloxacin Major
- Arsenic trioxide + Ofloxacin 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 Ofloxacin?
MediHelp rates the interaction as major. Ketoconazole and Ofloxacin 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 combined use increases the risk of torsades de pointes. Ketoconazole is also hepatotoxic, which is relevant given fluoroquinolone liver effects.
How serious is the interaction between Ketoconazole and Ofloxacin?
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 if possible; otherwise obtain baseline ECG, correct potassium and magnesium, and monitor the QTc and liver tests.
What other medicines interact with Ofloxacin?
MediHelp also lists interactions of Ofloxacin with, for example, Thioridazine, Adagrasib, Amiodarone. The full list is on the Ofloxacin page.
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