OBJECTIVES : Coronavirus disease 2019 (COVID-19) is an international public health emergency and there is a critical need to identify effective drugs. This document is a systematic review of published clinical experiences and in vitro studies using chloroquine (CQ) or hydroxychloroquine (HCQ) with or without Azithromycin for COVID-19 treatment.

METHODS : A systematic literature review was performed using Pubmed, Web of Science, Chinese Web of Knowledge and Google Scholar and clinical trials’ registries from inception to April 2, 2020.

RESULTS : We included 10 relevant articles; 4 in vitro studies, 2 RCTs, 3 observational studies and 1 editorial reporting pooled results from unpublished clinical trials.

CONCLUSIONS : In vitro studies showed that CQ and HCQ reduce SARS-CoV-2 replication. Regarding clinical trials, only few records were exploitable. Moreover, available data come mainly from observational studies or from very small sample controlled trials. As in RCTs, observational studies showed contradictory results regarding the efficacy of HCQ with or without azithromycin and had many limitations. Therefore, there is no high-quality evidence that these treatments improve outcomes in COVID-19. The results described in some trials can justify a further exploration either within the framework of ethically approved RCTs or Monitored Emergency Use of Unregistered and Investigational Interventions if RCTs are not possible.