Efficacy and Safety of Hydroxychloroquine and Chloroquine for Treating COVID-19: A Rapid Review

Abstract Background: Since its emergence, COVID-19 has affected more than one million people with over 100,000 deaths globally as of early April 2020. In this review, we evaluated the efficacy and safety of hydroxychloroquine and chloroquine on patients with COVID-19. Methods: PubMed, CENTRAL, Google Scholar, Chinese Clinical Trial Registry and Trial Registers: ISRCTN; UMIN-CTR (Japan's Trial Register); and the WHO portal up were searched for the in vitro and in vivo studies of hydroxychloroquine and chloroquine.Results: Moderate-certainty evidence from a single published RCT to-date showed that after a five-days treatment, patients on hydroxychloroquine may have shorter symptom duration compared to the control group, including fever (MD-1.0 day (95% CI -1.48, -0.52), cough (MD -1.1 day (95% CI -1.63, -0.57) and higher likelihood of having improved chest CT appearance (RR 1.47 (95% CI 1.02, 2.11), no clear differences was observed in the risk of progressing to severe illness and risk of adverse effects. A single non-randomized study showed marked decreased in the number with positive viral load at day 6, but due to several flaws in the study, the certainty of evidence for the outcome was very low.Conclusion: Despite the evidence on possible effects of hydroxychloroquine and chloroquine, given the paucity of available evidence especially in relation to the number on-going RCTs, conclusion on the effectiveness and safety of hydroxychloroquine cannot yet be made.