Chloroquine and hydroxychloroquine as a repurposed agent against COVID-19: a narrative review

The predicament arising from the coronavirus disease 2019 (COVID-19) pandemic has become one of the most significant modern public health challenges. Despite uncertainties in the viral determinants and pathogenesis, it is crucial to accurately inspect all available evidence to construct accurate clinical guidelines for optimised patient care. This study aims to discuss the available evidence for the use of chloroquine (CQ) and hydroxychloroquine (HCQ) against COVID-19. Early in vitro studies of CQ/HCQ against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are convincing. But contradictory evidence exists on the clinical use of CQ/HCQ, either alone or in combination with azithromycin. As of now, there is no compelling clinical evidence on CQ, HCQ, and azithromycin in COVID-19 and the available evidence is limited to methodologically inferior non-randomised studies. Studies have also shown detrimental drug reactions to CQ and 'HCQ plus azithromycin', mainly cardiac side effects in hospitalised patients with coexisting cardiovascular comorbidities. Therefore, we recommend that physicians avoid high doses and exercise extreme caution in the compassionate use of CQ/HCQ, either alone or in combination with other antiviral drugs.