Pharmacokinetic interactions between atorvastatin and traditional herbal medicines, Banhabaekchulcheonmatang (Banxia Baizhu Tianma Tang) and Hwangryeonhaedoktang (Huang Lian Jie Du Tang) in healthy volunteers

Background Banhabaekchulcheonmatang (BBCT) and Hwangryeonhaedoktang (HRHDT) are traditional herbal medicines widely used in East Asia to treat post-stroke sequelae. This study evaluated the effects of BBCT and HRHDT on the pharmacokinetics of atorvastatin, a drug commonly prescribed for secondary stroke prevention. Methods An open-label, randomized, three-period, two-sequence trial was conducted in 14 healthy Korean participants. In the first period, participants received a single 40 mg dose of atorvastatin. In subsequent periods, BBCT or HRHDT was administered three times daily for five days, followed by co-administration with atorvastatin on day 6. Plasma concentrations of atorvastatin and its active metabolites were measured, and pharmacokinetic parameters were determined using non-compartmental analysis. Results Co-administration of BBCT reduced the maximum plasma concentration (C max ) of atorvastatin by 24% without affecting the area under the plasma concentration-time curve (AUC), whereas HRHDT decreased atorvastatin C max , AUC last , and AUC inf by 46.7%, 22.6%, and 21.1%, respectively. BBCT or HRHDT co-administration also reduced the C max , AUC last , and AUC inf of 2-hydroxy atorvastatin by 30.2% and 52.7%, 14.9% and 35.9%, and 14.8% and 32.0%, respectively. Conclusion Co-administration of atorvastatin with BBCT or HRHDT resulted in a weak-to-moderate reduction in systemic exposure to atorvastatin and 2-hydroxy atorvastatin, suggesting that careful monitoring may be warranted during concomitant use.