Abstract: Objective To analyze adverse drug reactions/events caused by chloroquine phosphate in COVID-19 patients in order to provide reference for safe use of drugs for COVID-19. Methods Case reports of ADR/AE caused by chloroquine phosphate in COVID-19 patients in Shenzhen between January 1, 2020 and March 6, 2020 were analyzed. Results The incidence of ADR/AE induced by chloroquine phosphate was 65.62%. Totally 21 cases were included. The male/female ratio was 1：1.1. Patients aged 30 to 39 and 50 to 59 were the most susceptible to ADR/AE, and the percentage was 38.10% and 23.81% respectively. Thirty-two COVID-19 patients were treated with chloroquine phosphate. ADR/AE were more likely to occur in the digestive system, circulatory system (including heart), neuromuscular system and eyes. Arrhythmia caused by chloroquine phosphate was deadly. The duration of liver injury was relatively short, 3.5 days on average. The risk of liver damage could be increased when chloroquine phosphate was combined with traditional Chinese medicine decoctions. ADR/AE could occur the day chloroquine phosphate was taken or as late as 9 days later, most of which occurred in 2 to 7 days after treatment. Conclusion In the process of treating COVID-19 with phosphate chloroquine, we should avoid using contraindicated drugs, minimize the combination of drugs, and closely observe adverse reactions/events that have to be dealt with without delay so as to ensure the safety of patients.

Key words: chloroquine phosphate, Corona Virus Disease 2019(COVID-19), adverse drug reactions/events