Abstract: Objective To study the effect of Danshen Dripping Pills on the pharmacokinetics and pharmacodynamics of warfarin, and to assess whether or not Danshen Dripping Pills alone has any anticoagulant activity. Methods A randomized, double-blind, placebo-controlled, two-way cross-over trial was designed.Twelve male healthy volunteers (6 person/group) were randomized to receive either Danshen Dripping Pills in the first treatment period and placebo in the second treatment period, or vice versa. In addition to their randomized trentment, all volunteers received a single dose of 5 mg warfarin ond 29 of each treatment period. Blood samples for assessment were taken at frequent intervals during each treatment period. Results Administration of Danshen Dripping Pills significantly increasedcmax、AUC0~144、AUC0~∞、t1/2 and significantly decreased CL/F of warfarin compared with placebo.In addition, Danshen Dripping Pills had clinically significant effect on the pharmacodynamic effects of warfarin, as assessed 144h after warfarin dosing by measurement of prothrombin time, activated partial thromboplastin time. Danshen Dripping Pills alone had significant effect on these indicators of the clotting process. Conclusion Usual doses of Danshen Dripping Pills seem to have significant effects on the pharmacokinetics and pharmacodynamics of single dose warfarin in healthy subjects.

Key words: Danshen Dripping Pills, Warfarin, pharmacokinetics, pharmacodynamics, drug interactions