Irinotecan Milk thistle

Milk thistle does not affect the pharmacokinetics of irinotecan. 

A pharmacokinetic study was undertaken in 6 patients who were being treated with intravenous irinotecan 125 mg/m once weekly for 4 weeks, followed by a 2 week rest period. Four days before the second dose of irinotecan, a 14-day course of 200 mg milk thistle seed extract (containing silymarin 80%) three times daily was started. The pharmacokinetics of irinotecan and its metabolites did not differ between week 1 (no milk thistle), week 2 (4 days of milk thistle) or week 3 (12 days of milk thistle). No dosage alterations would therefore be expected to be needed if milk thistle (standardised with silymarin 80%) is given with irinotecan. 

Human studies have indicated no interactions between milk thistle and indinavir (DiCenzo et al. 2003 Mills et al. 2005 Piscitelli et al. 2002), digoxin (Gurley et al. 2006b), or irinotecan (van Erp et al. 2005). 

No interaction between irinotecan and milk thistle was observed in patients undergoing chemotherapy with irinotecan (125 mg/m ) once a week along with 200 mg of orally administered milk thistle daily for 14 days (van Erp et al. 2005). 

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