Drug interactions
Itraconazole + Quercetin
Severity: Minor
Itraconazole and Quercetin: 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
Quercetin is a flavonoid supplement that may alter intestinal transporter activity and could reduce itraconazole absorption. The effect is poorly characterized and its clinical relevance is uncertain.
What this interaction means in plain words
Itraconazole and Quercetin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Possible modulation of P-glycoprotein; the mechanism is not firmly established.
What to do
Advise patients to avoid high-dose quercetin supplements during itraconazole therapy. Check itraconazole levels if there is concern about treatment response.
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 Itraconazole
- Alfuzosin + Itraconazole Contraindicated
- Alprazolam + Itraconazole Contraindicated
- Avanafil + Itraconazole Contraindicated
- Conivaptan + Itraconazole Contraindicated
- Dihydroergotamine intranasal + Itraconazole Contraindicated
- Dihydroergotamine + Itraconazole Contraindicated
Frequently asked questions
Can I take Itraconazole with Quercetin?
MediHelp rates the interaction as minor. Itraconazole and Quercetin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Quercetin is a flavonoid supplement that may alter intestinal transporter activity and could reduce itraconazole absorption. The effect is poorly characterized and its clinical relevance is uncertain.
How serious is the interaction between Itraconazole and Quercetin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise patients to avoid high-dose quercetin supplements during itraconazole therapy. Check itraconazole levels if there is concern about treatment response.
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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