Effects of herbal medicines on warfarin response

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Hi All,

 

Jiang X, Blair EY, McLachlan AJ. Investigation of the effects of herbal

medicines on warfarin response in healthy subjects: a population

pharmacokinetic-pharmacodynamic modeling approach. J Clin Pharmacol.

2006 Nov;46(11):1370-8. Faculty of Pharmacy, Building A15, the U Sydney,

NSW 2006, Australia; e-mail: andrewm Systematic

evidence regarding herb-drug interactions is lacking. This study investigated

herb-drug interactions with warfarin. S-warfarin concentration and response

(prothrombin complex activity) data from healthy subjects (n = 24) who

received a single warfarin dose (25 mg) and either St John's wort, Asian

ginseng, Ginkgo biloba, or ginger were analyzed using a population

pharmacokinetic-pharmacodynamic modeling approach. The ratio of S-

warfarin apparent clearance (CL/F) compared to control was 1.39 +/- 0.06

and 1.14 +/- 0.04 after St John's wort and Asian ginseng pretreatment,

respectively. Other pharmacokinetic and pharmacodynamic parameters

were unaffected. Coadministration of St John's wort significantly increased

S-warfarin CL/F, whereas treatment with Asian ginseng produced only a

moderate increase in CL/F. Ginkgo and ginger did not affect the

pharmacokinetics of warfarin in healthy subjects. None of the herbs studied

had a direct effect on warfarin pharmacodynamics. Studies in

anticoagulated patients are warranted to assess the clinical significance of

these herb-drug interactions. PMID: 17050802 [PubMed - in process]

 

Best regards,