Abstract
Since the first outbreak of Coronavirus Disease-2019 (COVID-19) in January 2020, the medical community has been pursuing effective countermeasures. Early in the pandemic, several small clinical and in vitro studies from France and China reported on the efficacy of chloroquine (CQ) and hydroxychloroquine (HCQ) against SARS-CoV-2 infections, which generated global attention towards these decades-old antimalarials (AM) and heralded numerous studies investigating their role in treating COVID-19. Despite several observational studies early in the pandemic affirming their beneficial role in treating COVID-19, 12 clinical studies reported no mortality benefits for CQ/HCQ in COVID-19 patients. The excitement over CQ/HCQ was ultimately quenched after three large randomized clinical trials, the COALITION-I trial in Brazil, the RECOVERY trial in the United Kingdom (UK), and the SOLIDARITY trial from World Health Organization (WHO) consistently reported no beneficial effects for CQ/HCQ in hospitalized COVID-19 patients. While initial studies suggested that CQ/HCQ might have a role in treating the early phases of infection, the results from three rigorously designed studies investigating their role in non-hospitalized COVID-19 patients were equivocal and inconsistent. Here we review the major social events related to the therapeutic use of CQ/HCQ in COVID-19, and the data from selected clinical studies evaluating their efficacy in hospitalized and non-hospitalized COVID-19 patients along with the major safety concerns.