Insights into the mechanisms of action of chloroquine and hydroxychloroquine and its use in COVID-19 for chemoprophylaxis

The global outbreak of coronavirus disease 2019  (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2  (SARS-CoV-2/2019-nCoV) has put forth a serious threat to international public health and has ruined the global economy. Till date, no drugs have been approved for coronavirus disease-2019  (COVID-19), although the use of some drugs in the trial phase has been attempted. The drugs being used for the management of COVID-19 disease include chloroquine  (CQ), hydroxychloroquine  (HCQ), and remdesivir. In this article, we have aimed to review existing literature and mechanism by which CQ and HCQ have an effect on COVID-19, most importantly by interfering with autophagy, lysosomal activity, receptor binding, and membrane fusion. We have systematically searched the PubMed database up to April 2020 and analyzed all the articles published on CQ, HCQ, and COVID-19. The available data provide insights into the immunomodulatory potency of HCQ, along with the molecular mechanism of action of the drug on the SARS-CoV-2.