Drug interactions
Ketoconazole + Rifaximin
Severity: Moderate
Ketoconazole and Rifaximin: 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
Ketoconazole inhibits P-glycoprotein and may increase absorbed rifaximin. Because baseline systemic exposure is very low, the impact is usually small but could matter in severe hepatic dysfunction.
What this interaction means in plain words
Ketoconazole and Rifaximin 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; Rifaximin belongs to Anti Bacterial.
Why it happens
P-glycoprotein inhibition by ketoconazole decreases rifaximin efflux.
What to do
Monitor for rifaximin adverse effects and avoid dose escalation, particularly in hepatic impairment.
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 Rifaximin
- Cholera vaccine + Rifaximin Major
- Microbiota + Rifaximin Major
- Amiodarone + Rifaximin Moderate
- Bcg intravesical live + Rifaximin Moderate
- Cyclosporine + Rifaximin Moderate
- Cyclosporin + Rifaximin Moderate
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 Rifaximin?
MediHelp rates the interaction as moderate. Ketoconazole and Rifaximin 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 inhibits P-glycoprotein and may increase absorbed rifaximin. Because baseline systemic exposure is very low, the impact is usually small but could matter in severe hepatic dysfunction.
How serious is the interaction between Ketoconazole and Rifaximin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for rifaximin adverse effects and avoid dose escalation, particularly in hepatic impairment.
What other medicines interact with Rifaximin?
MediHelp also lists interactions of Rifaximin with, for example, Cholera vaccine, Microbiota, Amiodarone. The full list is on the Rifaximin page.
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