Effects Of Korean Red Ginseng On The Pharmacokinetics And Pharmacodynamics Of Metformin In Healthy Subjects

Abstract

Characterizing potential interactions between red ginseng, an herb with desirable health effects, and metformin, a commonly used drug for the treatment of type 2 diabetes mellitus, is of high clinical importance. In this study, we evaluate the effects of Korean red ginseng on the pharmacokinetic and pharmacodynamic properties of metformin in healthy subjects. The study was conducted in an open-label, two-period and single-sequence design. A total of 11 subjects received multiple doses of metformin in the first study period followed by multiple doses of metformin and red ginseng in the second study period. The Geometric Mean Ratio (GMR) (90% Confidence Interval (CI)) between the groups for area under the plasma drug concentration-time curve within a dosing interval (tau) at steady state (AUCtau,ss) of metformin was out of the range of bioequivalence, indicating that the systemic exposure of metformin when combined with red ginseng was reduced compared with administration of metformin alone. However, the pharmacodynamic analysis showed that the GMR (90% CI) between the groups for area under the blood glucose values–time curve from time zero to the time of the last measurable value (AUClast) and maximum blood glucose value (Gmax) were within the range of bioequivalence. We concluded that the observed reduction in the systemic exposure of metformin when administered with red ginseng is clinically insignificant. This study demonstrated that Korean red ginseng did not have clinically significant pharmacokinetic or pharmacodynamic herb–drug interactions with metformin in healthy subjects.