Drug interactions
Irinotecan + Milk thistle
Severity: Minor
Irinotecan and Milk thistle: 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
Milk thistle constituents may weakly inhibit UGT1A1 in vitro, but clinical studies show no meaningful change in irinotecan exposure. Clinically significant interaction is unlikely.
What this interaction means in plain words
Irinotecan and Milk thistle 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 weak UGT1A1 inhibition by silymarin, not shown to be clinically significant.
What to do
No routine action required; monitor for diarrhoea and neutropenia as usual.
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 Irinotecan
- Clozapine + Irinotecan Contraindicated
- Irinotecan + Sacituzumab govitecan Contraindicated
- Adenovirus types 4 and 7 live + Irinotecan Major
- Apalutamide + Irinotecan Major
- Atazanavir + Irinotecan Major
- Carbamazepine + Irinotecan Major
Frequently asked questions
Can I take Irinotecan with Milk thistle?
MediHelp rates the interaction as minor. Irinotecan and Milk thistle have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Milk thistle constituents may weakly inhibit UGT1A1 in vitro, but clinical studies show no meaningful change in irinotecan exposure. Clinically significant interaction is unlikely.
How serious is the interaction between Irinotecan and Milk thistle?
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 routine action required; monitor for diarrhoea and neutropenia as usual.
What other medicines interact with Irinotecan?
MediHelp also lists interactions of Irinotecan with, for example, Clozapine, Sacituzumab govitecan, Adenovirus types 4 and 7 live. The full list is on the Irinotecan page.
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