In recent years,a large number of drugs have been withdrawn from the market because of torsade de pointes(TdP) and sudden cardiac death,which pose great risks in drug application.Therefore,the different models have been developed to detect TdP liability during the early stage of drug development.In this paper,the principles and characteristics of these screening models are reviewed to give props for preclinical safety assessment.

Objective To retrospectively analyze adverse drug reaction ( ADR ) of Yuxingcao ( Houttuyniae Herba ) preparations, thus provide reference for post-market re-evaluation of traditional Chinese medicine injections. Methods The ADR from Chinese ADR spontaneous reporting system database from 2006 to 2008 were analyzed by descriptive statistic method. Results A total of 2 282 reports on ADR induced by Yuxingcao preparations were concluded in this study, and 98.07% ADR of the total cases ( 2 238 case ) were due to vein injection. The main ADR were anaphylactic reactions which injure multiple systems and organs.The most frequent symptoms were respiratory system damage, such as expiratory dyspnea (with the incidence rate of 27.25%).Skin and mucous membrane were the secondly susceptible (with the incidence rate of 21.35%).The ratio of serious ADR in the total case was 13.50% (308 case), rate of allergic shock was 8.37% (191 case), and 22 cases were dead. Conclusion By strengthening the ADR reporting and monitoring, the risk of traditional Chinese medicine injection could be controlled.Safety re-evaluation should be performed to overall enhance safety, effectiveness and quality control of these kinds of medicine.