clinical efficacy of hydroxychloroquine or chloroquine in patients with covid-19: an umbrella review

Background: many of the known coronaviruses cause a wide range of respiratory infections in humans, and the novel coronavirus is no exception to this rule. although no drug has yet been discovered to prevent or treat this disease, chloroquine (cq) and hydroxychloroquine (hcq)have been widely used in studies showing different results. methods: the present study is an umbrella study. the search was conducted for the articles published from january 2020 to november 2020 using the keywords (covid-19 or sars-cov-2 and hydroxychloroquine or chloroquine and systematic review ormetanalysis). this study was limited to human samples and systematic reviews with or without meta-analysis. the quality of the articles was also evaluated independently by two researchers. results: to evaluate the clinical efficacy of hcq and cq, a total of 176 papers and 643569 cases ranging from patients with mild pneumonia to intubated critically ill patients were evaluated. finally, 8 studies were included. conclusion: there are conflicting results regarding hcq or cq efficacy and safety in the systematic reviews. more evidence is needed to confirm whether these drugs are useful in covid-19 infection, and their usage as the standard care cannot be recommended based on the majority of the studies included in this umbrella review.