Effects of Schisandra sphenanthera extract on the pharmacokinetics of tacrolimus in healthy volunteers.
OBJECTIVE
To assess the effect of Schisandra sphenanthera extract (SchE) on the pharmacokinetics of tacrolimus in healthy volunteers.


METHODS
Twelve healthy male volunteers were orally treated with SchE, three capsules twice daily for 13 days. Pharmacokinetic investigations of oral tacrolimus administration at 2 mg were performed both before and at the end of the SchE treatment period. Whole blood tacrolimus concentrations were determined by enzyme-linked immunosorbent assay. Estimated pharmacokinetic parameters before and with SchE were calculated with noncompartmental techniques.


RESULTS
Following administration of SchE, the average percentage increases of individual increases in AUC, AUMC and C(max) of tacrolimus were 164.2% [95% confidence interval (CI) 70.1, 258.4], 133.1% (95% CI 49.5, 261.3) and 227.1% (95% CI 155.8, 298.4), respectively (P < 0.01 or 0.05). On average, there was a 36.8% (95% CI 13.4, 60.2) increase in tacrolimus t(max) (P < 0.01). The average percentage decreases in CL/F and V/F were 49.0% (95% CI 31.1, 66.9) and 53.7% (95% CI 40.1, 67.4), respectively (P < 0.01).


CONCLUSIONS
SchE can increase the oral bioavailability of tacrolimus. The results of this study will add important information to the interaction area between drugs and herbal products.
Xin
Hua-Wen
HW
Department of Clinical Pharmacology, Wuhan General Hospital, Wuhan, China.
Wu
Xiao-Chun
XC
Li
Qing
Q
Yu
Ai-Rong
AR
Zhu
Min
M
Shen
Yang
Y
Su
Dan
D
Xiong
Lei
L
D000328:Adult; D004347:Drug Interactions; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology*; D032141:Schisandra; D016559:Tacrolimus / Q000097:blood / Q000493:pharmacokinetics*
D007166:Immunosuppressive Agents; D010936:Plant Extracts; D016559:Tacrolimus