title: Paeoniae Radix, a traditional Chinese medicine, and CYP2C9 activity.
abstract: Paeoniae Radix (PR) is a commonly used traditional Chinese medicine. A slight effect of PR on the pharmacokinetics of phenytoin that is mainly metabolised by CYP2C9 has been reported. The aim of this pilot study was to clarify if PR has an effect on losartan oxidation used as a measure of CYP2C9 activity. Three healthy volunteers received a single oral dose of losartan before and after PR treatment. Losartan and E-3174, an active metabolite of losartan, were analysed in 8 hour urine. PR did not seem to have an effect on CYP2C9 activity when the losartan/E-3174 ratios were compared before and after PR treatment (P = 0.56) although a larger study would need to be undertaken to confirm this finding.
authors.forename: Han-Jing
authors.initials: HJ
authors.lastname: Xie
authors.forename: Umit
authors.initials: U
authors.lastname: Yasar
authors.forename: Mia
authors.initials: M
authors.lastname: Sandberg
authors.forename: Anders
authors.initials: A
authors.lastname: Rane
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004347:Drug Interactions; D006801:Humans; D007093:Imidazoles / Q000652:urine; D019808:Losartan / Q000008:administration & dosage / Q000652:urine; D008516:Medicine, Chinese Traditional; D029596:Paeonia / Q000737:chemistry*; D008517:Phytotherapy; D028321:Plant Preparations / Q000494:pharmacology*; D013777:Tetrazoles / Q000652:urine
chemical_list: D007093:Imidazoles; D028321:Plant Preparations; D013777:Tetrazoles; D003577:Cytochrome P-450 Enzyme System; C066026:losartan carboxylic acid; D019808:Losartan