Drug discovery of small molecules for the treatment of COVID-19: A review on clinical studies

: Recently, a sudden outbreak of novel coronavirus disease (COVID-19) was caused by a zoonotic virus known as severe acute respiratory syndrome coronavirus (SARS-CoV-2). It has caused pandemic situations around the globe and affecting the lives of millions of people. So far, no drug has been approved for the treatment of SARS-CoV-2 infected patients. As of now, more than 1000 clinical trials are going on for repurposing of FDA approved drugs and for evaluating the safety & efficiency of experimental antiviral molecules to combat COVID-19. Since the development of new drugs may require months to years to reach the market, this review focusses on the potentials of existing small molecule FDA approved drugs and the molecules already in the clinical pipeline against viral infections like HIV, hepatitis B, Ebola virus, and other viruses of coronavirus family (SARS-CoV and MERS-CoV). The review also discusses the natural products and traditional medicines in clinical studies against COVID-19. Currently, 1978 studies are active, 143 completed and 4 posted results (as on June 13, 2020) on clinicaltrials.gov.