School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
Evid Based Complement Alternat Med. 2014;2014:957362. doi: 10.1155/2014/957362. Epub 2014 Mar 18.
Increasing and inadvertent use of herbs makes herb-drug interactions a focus of research. Concomitant use of warfarin, a highly efficacious oral anticoagulant, and herbs causes major safety concerns due to the narrow therapeutic window of warfarin. This paper presents an update overview of clinical findings regarding herb-warfarin interaction, highlighting clinical outcomes, severity of documented interactions, and quality of clinical evidence. Among thirty-eight herbs, Cannabis, Chamomile, Cranberry, Garlic, Ginkgo, Grapefruit, Lycium, Red clover, and St. John's wort were evaluated to have major severity interaction with warfarin. Herbs were also classified on account of the likelihood of their supporting evidences for interaction. Four herbs were considered as highly probable to interact with warfarin (level I), three were estimated as probable (level II), and ten and twenty-one were possible (level III) and doubtful (level IV), respectively. The general mechanism of herb-warfarin interaction almost remains unknown, yet several pharmacokinetic and pharmacodynamic factors were estimated to influence the effectiveness of warfarin. Based on limited literature and information reported, we identified corresponding mechanisms of interactions for a small amount of "interacting herbs." In summary, herb-warfarin interaction, especially the clinical effects of herbs on warfarin therapy should be further investigated through multicenter studies with larger sample sizes.
由于华法林（一种高效口服抗凝剂）的治疗窗较窄，因此在同时使用华法林和草药时，会引起严重的安全问题，这使得草药-药物相互作用成为研究的重点。本文综述了有关草药-华法林相互作用的临床研究结果，重点介绍了临床结局、已记录的相互作用的严重程度以及临床证据的质量。在 38 种草药中，大麻、甘菊、蔓越莓、大蒜、银杏、葡萄柚、枸杞、红三叶草和贯叶金丝桃被评估为与华法林有严重的相互作用。此外，还根据草药支持相互作用证据的可能性对其进行了分类。有四种草药被认为极有可能与华法林发生相互作用（一级），三种被估计为可能（二级），另外十种和二十一种分别被认为是可能（三级）和可疑（四级）。草药-华法林相互作用的一般机制尚不清楚，但有几个药代动力学和药效学因素被认为会影响华法林的疗效。基于有限的文献和已报道的信息，我们确定了少量“相互作用草药”的相应相互作用机制。总之，草药-华法林相互作用，尤其是草药对华法林治疗的临床影响，应通过更大样本量的多中心研究进一步研究。
