Midazolam Echinacea

Echinacea does not appear to alter the AUC and clearance of oral midazolam, although the bioavailability may be increased. Clearance of intravenous midazolam may be increased in patients taking echinacea. 

The findings of the first study with oral and intravenous midazolam suggest that the effect of echinacea on CYP3A4 substrates might depend on the whether they have high or low oral bioavailability and whether they have high or low hepatic clearance. Further study is needed. 

Research was conducted on a proprietary Echinacea purpurea extract, identified as an 8 1 extract of fresh E. purpurea root and flower. In healthy volunteers orally administered 8 mg midazolam (a substrate of GYP3A) and 120 mg fexofenadine (a substrate of P-gp) before and after administration of 1500 mg per day of this extract for 14 days, a decrease in plasma levels (AUCq. ) of midazolam was observed, suggesting induction of the drug metabolizing enzyme CYP3A. 

---