Hydroxychloroquine: A review of its effects on viral replication based on current literature

Abstract

Quinine has been used for centuries as a drug for malaria treatment. Chloroquine (CQ) and its 4-aminoquinoline analog hydroxychloroquine (HCQ) have been used during the last two centuries for the treatment and prophylaxis of malaria. Since the inception of COVID-19 in Wuhan, China, in late December 2019, physicians and researchers have tried to use old drugs to treat this pandemic. This review discusses possible modes of action of CQ and HCQ in vitro that might treat this viral infection. The diverse cellular, immunological, and antiviral mechanisms reported in the literature suggest that CQ and HCQ might be useful drugs against COVID-19. Both drugs increase the pH in intracellular organelles, which limits viral replication. However, randomized controlled trials have not found any benefit as either for prophylaxis or treatment of COVID-19. In addition, fatal adverse events associated with these drugs have resulted in the issuance of precautionary measures when recommending these drugs in COVID-19 patients. The search for other innovative drugs to cure COVID-19 and an expedited approval for a vaccine are ongoing at present.