Hydroxychloroquine and chloroquine in prophylaxis and treatment of COVID-19: What is known?

The corona virus disease-19 (COVID-19) pandemic has affected the entire world causing huge economic losses and considerable morbidity and mortality. Considering the explosive growth of the pandemic repurposing existing medicines may be cost-effective and may be approved for use in COVID-19 faster. Researchers and medical practitioners worldwide have explored the use of chloroquine and hydroxychloroquine, in few occasions combined with the macrolide antibiotic azithromycin, for COVID-19 treatment. These two drugs are economic and easily available, and hence gained attention as a potential option for COVID-19 management. As per the available evidence, the outcomes of treatments with these medications are conflicting from both the efficacy and safety (predominantly cardiac related) perspectives. Currently, multiple studies are underway to test the safety and efficacy of these medications and more results are expected in the near future. The retina, the endocrine system (with risk of hypoglycemia), the musculoskeletal system, the hematological system, and the neurological system may also be affected. The use of these drugs is contraindicated in patients with arrhythmias, known hypersensitivity, and in patients on amiodarone. In addition to the published literature, personal communication with doctors treating COVID-19 patients seems to suggest the drugs may be effective in reducing symptoms and hastening clinical recovery. The literature evidence is still equivocal and further results are awaited. There has been recent controversy including retraction of articles published in prestigious journals about these medicines. Their low cost, long history of use, and easy availability are positive factors with regard to use of these drugs in COVID-19.