Chloroquine and hydroxychloroquine: Current evidence for their effectiveness in treating COVID-19

Abstract

Verdict: Several in vitro studies report antiviral activity of chloroquine and hydroxychloroquine against SARS-CoV-2. In vivo data, although promising, is currently limited to one study with considerable limitations. On the basis of the weak evidence available to date, treatment guidelines have already incorporated the usage of chloroquine/hydroxychloroquine for certain patients with COVID-19. Further research should address the optimal dose and duration of treatment, and explore side effects and long-term outcomes. There is a higher risk of side effects in the presence of renal and liver impairment, and there have been isolated reports of COVID-19 disease-causing renal and hepatic injury. Over twenty in vivo clinical trials have already been registered to test the use of chloroquine and hydroxychloroquine for the treatment of COVID-19. Contraindications for the use of these drugs must be checked for each individual before treatment. Empirical evidence suggests that hydroxychloroquine has a better safety profile, and it might therefore be preferable to focus research efforts on this less toxic metabolite.