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Warfarin: New Dietary Concerns

KEY POINT

Warfarin therapy may need to be more closely monitored after patients begin use of dietary supplements such as ginseng or glucosamine or change their intake of cranberry products, according to cases and small studies.

SOURCES

Yuan C-S, Wei G, Dey L, et al. Brief communication: American ginseng reduces warfarin’s effect in healthy patients: a randomized, controlled trial. Ann Intern Med. 2004;141:23–7.

Jiang X, Williams KM, Liauw WS, et al. Effect of St John’s wort and ginseng on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects. Br J Clin Pharmacol. 2004;57:592–9.

Janetzky K, Morreale AP. Probable interaction between warfarin and ginseng. Am J Health Syst Pharm. 1997;54:692–3.

Grant P. Warfarin and cranberry juice: an interaction? J Heart Valve Dis. 2004;13:25–6. 

Suvarna R, Pirmohamed M, Henderson L. Possible interaction between warfarin and cranberry juice. BMJ. 2003;327:1454. 

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