Drug interactions
Itraconazole + Rifabutin
Severity: Major
Itraconazole and Rifabutin: major interaction.
Last updated Sources: US FDA label
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
Rifabutin induces itraconazole metabolism and can drop antifungal levels to ineffective concentrations. Itraconazole in turn raises rifabutin levels, which increases the risk of uveitis, neutropenia and other toxicity.
What this interaction means in plain words
Itraconazole and Rifabutin 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.
Itraconazole belongs to Anti Fungals; Rifabutin belongs to Anti Bacterial.
Why it happens
Rifabutin induces CYP3A4, lowering itraconazole, while itraconazole inhibits CYP3A4 and raises rifabutin concentrations.
What to do
Avoid the combination and use a non-interacting antifungal or antimycobacterial. If unavoidable, monitor itraconazole levels and watch for rifabutin toxicity such as uveitis and neutropenia.
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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References
Other interactions of Itraconazole
- Alfuzosin + Itraconazole Contraindicated
- Alprazolam + Itraconazole Contraindicated
- Avanafil + Itraconazole Contraindicated
- Conivaptan + Itraconazole Contraindicated
- Dihydroergotamine intranasal + Itraconazole Contraindicated
- Dihydroergotamine + Itraconazole Contraindicated
Other interactions of Rifabutin
- Cabotegravir + Rifabutin Contraindicated
- Lorlatinib + Rifabutin Contraindicated
- Rifabutin + Voriconazole Contraindicated
- Apixaban + Rifabutin Major
- Axitinib + Rifabutin Major
- Brexpiprazole + Rifabutin Major
Frequently asked questions
Can I take Itraconazole with Rifabutin?
MediHelp rates the interaction as major. Itraconazole and Rifabutin 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. Rifabutin induces itraconazole metabolism and can drop antifungal levels to ineffective concentrations. Itraconazole in turn raises rifabutin levels, which increases the risk of uveitis, neutropenia and other toxicity.
How serious is the interaction between Itraconazole and Rifabutin?
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 the combination and use a non-interacting antifungal or antimycobacterial. If unavoidable, monitor itraconazole levels and watch for rifabutin toxicity such as uveitis and neutropenia.
What other medicines interact with Itraconazole?
MediHelp also lists interactions of Itraconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Itraconazole page.
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