Effects of Danshen capsules on the pharmacokinetics and pharmacodynamics of clopidogrel in healthy volunteers.

Nowadays, the Herb-drug combination is becoming increasingly popular in China. However, the possible interaction induced by their combination was examined rarely. The aim of this study was to investigate the effect of multi-dose administration of Danshen capsules on clopidogrel pharmacokinetics and pharmacodynamics in healthy volunteers. A sequential, open-label, and two-period pharmacokinetic drug interaction study was designed to compare clopidogrel pharmacokinetic parameters before and after 7 days of administration of Danshen capsules in twenty healthy male volunteers. Co-administration of multiple doses of Danshen capsules caused increases in apparent oral clearance of clopidogrel and its metabolite by 96.5% and 73.7% and apparent volume of distribution by 94.2% and 75.1%, corresponding declines in C by 41.7% and 32.9%, AUC by 50.3% and 41.8%, and AUC by 49.3% and 41.5% in human volunteers, respectively. Corresponding pharmacokinetic findings, co-administration of Danshen capsules with clopidogrel decreased the antiplatelet activity compared with individual agents. The results suggested that multiple dose administration of Danshen capsules could induce cytochrome P450 (CYP) isoenzymes, thereby increasing the clearance of clopidogrel. Therefore, caution should be taken when Danshen products containing lipophilic components are used in combination with therapeutic drugs metabolized by CYP3A4.