How can traditional Chinese medicine contribute to the therapeutic approach in coronavirus disease 2019 (COVID-19)? A review of the registered clinical trials
Authors: Luo Hui , Yang Ming , Tang Qiao-ling , Hu Xiao-yang , Willcox Merlin L. , Liu Jian-ping 
Published: June 2020

Abstract
Background: Since the outbreak of coronavirus disease 2019 (COVID-19) in January 2020, Traditional Chinese Medicine (TCM) has been fully and deeply involved in the treatment of COVID-19 in China. An increasing number of clinical trials has been registered to evaluate the effects of TCM in the prevention and therapeutic management of COVID-19.Objective: This study aims to review the existing TCM registered trials, identify promising and available TCM therapies, in order to provide reference for the global management of COVID-19. Methods: All clinical trials on TCM for COVID-19 registered in eight registry platforms worldwide were searched up to May 14, 2020. The data of registration trend, design, objective, interventions, current status, and relevant information were reviewed and summarized. Supportive information on the progress, results and potential value of the included registered trials were searched and reviewed from databases and official websites. Results: 161 TCM trials registered in three registries from January 26 to May 14 were included. 94 (58.4%) were randomized controlled trials, followed by controlled clinical trials (25, 15.5%), single-arm clinical studies (18, 11.2%) and others (24, 14.9%). 114 trials (70.8%) assessed therapeutic effects; while the remaining were for prevention, rehabilitation, and TCM syndrome epidemiology. The three most evaluated TCM interventions were Chinese herbal medicine (CHM) in the preparation forms of formulae decoction/granule (41.7%), Chinese patent medicine (24.8%) and Chinese herbal-derived injections (8.1%). The common outcomes in therapeutic trials were symptoms and signs (65.8%), time to viral clearance on PCR (50.9%), and improvement in CT images (43.9%). 78 trials (48.4%) had started recruiting and six trials (3.7%) had completed recruiting. Among the TCM interventions identified from the registered trials, the following are worthy of attention and may have the potential feasibility of being evaluated and then used worldwide due to their rigorous design, previous evidence and availability: for prevention in high-risk populations or suspected cases, moxibustion, Huoxiang Zhengqi pill and Jinye Baidu granule could be considered; for treatment, Qingfei Paidu decoction or granules in mild, moderate and severe cases, Huashi Baidu decoction, Lianhua Qingwen caplsule, Toujie Quwen granule and Xiyanping injection in mild and moderate cases, and Xuebijing injection in severe cases could be considered. For rehabilitation of cured patients, the effect of Tai Chi and Liuzijue on the patients’ lung function and quality of life deserves attention.Conclusion: A series of promising potentially effective TCM interventions including CHM formulae, Chinese patent medicines, herbal-derived injections and non-drug therapies have been identified in clinical practice and are being evaluated by registered clinical trials. Available and applicable interventions within relevant trials are worthy of worldwide attention and application, in order to contribute to the global management of COVID-19 epidemic.