Interaction between warfarin and Korean red ginseng in patients with cardiac valve replacement.

BACKGROUND: The objective of this study was to determine whether an interaction exists between warfarin and Korean red ginseng. METHODS: A prospective, double-blind, randomized, two-period crossover study was conducted on 25 patients with cardiac valve replacement under warfarin therapy. Either Korean red ginseng 1 g or placebo (hop extract 0.25 g, caramel color 0.05 g, and red ginseng flavor 0.03 g) was concomitantly administered with warfarin. INR and warfarin concentrations were analyzed on the 3rd and 6th weeks of each study period. RESULTS: The INR changes on the 3rd and 6th weeks of Korean red ginseng administration were -0.16±0.95 and -0.14±0.94 whereas those of placebo were -0.03±0.65 and 0.25±0.95; there were no statistically significant differences in mean INR changes. CONCLUSION: Korean red ginseng could be used with close monitoring and under appropriate education in patients who take warfarin.