Drug interactions
Ketoconazole + Metronidazole
Severity: Minor
Ketoconazole and Metronidazole: minor 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
Metronidazole may slightly increase ketoconazole concentrations, with little clinical significance reported. Both drugs can cause gastrointestinal upset and hepatotoxicity, and both may rarely prolong QT.
What this interaction means in plain words
Ketoconazole and Metronidazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Ketoconazole belongs to Anti Fungals; Metronidazole belongs to Anti Parasitic.
Why it happens
Possible weak CYP3A4 inhibition; the mechanism is not well established.
What to do
No dose adjustment is typically needed; monitor liver function with prolonged combined use.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Other interactions of Metronidazole
- Ethanol + Metronidazole Contraindicated
- Metronidazole + Pimozide Contraindicated
- Amiodarone + Metronidazole Major
- Disulfiram + Metronidazole Major
- Ergotamine + Metronidazole Major
- Lomitapide + Metronidazole Major
Frequently asked questions
Can I take Ketoconazole with Metronidazole?
MediHelp rates the interaction as minor. Ketoconazole and Metronidazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Metronidazole may slightly increase ketoconazole concentrations, with little clinical significance reported. Both drugs can cause gastrointestinal upset and hepatotoxicity, and both may rarely prolong QT.
How serious is the interaction between Ketoconazole and Metronidazole?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose adjustment is typically needed; monitor liver function with prolonged combined use.
What other medicines interact with Ketoconazole?
MediHelp also lists interactions of Ketoconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Ketoconazole page.
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