Case Report DOI 10.3349/ymj.2010.51.5.793 pISSN: 0513-5796, eISSN: 1976-2437 Yonsei Med J 51(5):793-796, 2010 Interaction between Warfarin and the Herbal Product Shengmai-Yin: A Case Report of Intracerebral Hematoma Qun Su1 and Yuhong Li2 1Intensive Care Unit, 2Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China. Received: February 4, 2010 Revised: March 15, 2010 Accepted: March 21, 2010 Corresponding author: Dr. Yuhong Li, Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Zhejiang University, 79 Qingchun Road, 310003, Hangzhou, China. Tel: 86-13758147990, Fax: 86-57187236818 E-mail: yuh_li@hotmail.com ∙The authors have no financial conflicts of interest. © Copyright: Yonsei University College of Medicine 2010 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non- Commercial License (http://creativecommons.org/ licenses/by-nc/3.0) which permits unrestricted non- commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. A 71-year-old man was stable on warfarin (2.25 mg daily) therapy with an international normalized ratio (INR) of 1.8-2.2 after a heart valve replacement surgery. Recently, he consumed the liquid-like herbal product called shengmai-yin (10 mL daily) against medical advice. Seven days after the daily consumption of shengmai-yin, he was admitted to the intensive care unit because of consciousness disturbance [Glasgow Coma Scale (GCS) score 7] with an INR of 5.08. Head com- puted topography revealed intracerebral hematoma in the left temporoparietal region. Both warfarin therapy and the herbal product were withdrawn. At the same time, therapy with intravenous vitamin K1 40 mg was started. On the second day of admission, craniectomy was performed to remove the intacerebral hematoma under general anesthesia. He remained confused and restless for 2 days, but then showed progressive recovery in the consciousness level as well as motor and verbal functions. Shengmai-yin contains herbal ingredients that can interact with warfarin. The Drug Interaction Probability Scale (DIPS) indicated that warfarin and shengmai-yin were highly probable causes of intracerebral hematoma. Pati- ents on warfarin therapy should be discouraged from taking herbal medicines, especially preparations that are already known to have antiplatelet and antithrom- botic effects. Key Words: Intracerebral hemorrhage, warfarin, shengmai-yin INTRODUCTION The anticoagulation warfarin is a commonly prescribed medication that has a narrow therapeutic index and displays high inter- and intrasubject variability in response. In the community there is also widespread, often unreported, self- medication with a range of herbal medicines. The opportunity for potentially life- threatening interactions between herbal medications and warfarin is thus high.1 Shengmai-yin is one such herbal medicine that is commonly used for coronary heart disease, cardiogenic shock, and septic shock for promoting microcirculation and decreasing blood viscosity as well for a wide range of the other indications.2-4 However, relatively little is known about shengmai-yin drug interactions. This is the first report of an adverse interaction between warfarin and a combination herbal product, shengmai-yin, resulting in cerebral bleeding. Yonsei Med J http://www.eymj.org Volume 51 Number 5 September 2010 793