The search for effective treatment options for COVID-19 has resulted in research to assess whether medication that are currently used for other diseases and infections such as malaria or lupus, may be effective. Chloroquine, and a related drug, hydroxychloroquine, have been shown to reduce the viral activity of viruses within the same family as the SARS-CoV-2 (the virus that causes COVID-19) when they have been tested in cell and animal studies. Research in humans, however, have not been shown to be safe or effective. Despite the lack of evidence to prove that it works in humans, regulatory agencies in various countries authorised the use of these medications for the treatment of COVID-19 while research is being conducted to find out whether these drugs are effective for this respiratory infection. Thus far, clinical studies have failed to show that the administration of these drugs in patients infected with COVID-19 improves their outcome. Additionally, some studies have shown that these agents may be associated with cardiac side effects such as heart rhythm disturbances, which may be due to the high doses that need to be given to treat COVID-19. Timely responses to pandemics such as this may, at times, require the use of medication that has not been fully tested and formally approved for the specific disease. However, certain ethical concerns must be addressed in the manner in which potentially useful medications that have not been formally approved are used. The decision to use medications for non-approved conditions should be carefully thought through, and should preferably be performed using guidelines such as the Monitored emergency use of unregistered and investigational interventions framework that have been developed for such situations.
Although chloroquine and hydroxychloroquine have not yet been shown to be safe or effective for the treatment or prevention of COVID-19, regulatory agencies in some countries have authorised their use in Coronavirus disease 2019 (COVID-19) due to the lack of available interventions. Several large clinical trials are currently underway to investigate these agents as potential therapeutic options for COVID-19. Previous research against similar pathogens that cause severe acute respiratory syndrome and Middle East respiratory syndrome has identified chloroquine and hydroxychloroquine as possible antiviral candidates against SARS-CoV-2. Despite promising pre-clinical evidence, data have thus far failed to confirm their efficacy, and recent studies suggest potential dose-related cardiotoxicity and mortality. Close monitoring for cardiac conduction abnormalities is advised with higher-than-approved doses. Additional, robust evidence from randomised controlled trials and meta-analyses are required to make informed risk-benefit assessments. Finally, the off-label prescription of these agents should be judiciously considered, and any such use should be conducted within clinical trials, or under the Monitored Emergency Use of Unregistered and Investigational Interventions framework.