COVID-19 and the Challenges of Chemotherapy: The Failure Case of Hydroxychloroquine in the Clinical Treatment of SARS-CoV-2 Infection

Abstract:: In December 2019, in Wuhan, China, an outbreak of a respiratory disease was reported, and the causative agent of which was discovered to be the new coronavirus. This disease spread rapidly around the world, and in March 2020, the WHO declared a state of pandemic. According to the WHO situation in October report, more than 41,570.883 were affected, and 1,134.940 deaths had occurred. Thus, the urgency to find therapeutic targets to prevent viral replication and a vaccine to protect against the disease became a great challenge for researchers around the world. A French group began using, in patients, a drug that had already been approved for human use, hydroxychloroquine (HQ) alone or in combination with azithromycin. The use of a drug already approved by regulatory agencies can enable treatment strategies to be put in place rapidly; however, even though in vitro may indicate success, this is not always guaranteed. For HQ, some studies have shown a satisfactory response in patients, while in many others, the result was not positive and patients actually died. Furthermore, many adverse effects of HQ have been described. In this review, we will briefly discuss how this therapy became an option for the treatment of SARS-CoV-2 infection. We will address the use of HQ in different pathologies and COVID-19 specifically; describing the doses used, as well as the main adverse effects. The take-home message is that more efforts are still required to conclude the efficacy of HQ against COVID-19, however, most of the studies carried out currently are showing that the use of HQ does not bring benefits during treatment of COVID-19.