Elucidating the Drug Repurposing Spectra of COVID-19 with its Analogues SARS and MERS

Corona Virus Disease-2019 (COVID-19), caused by the SARS CoV-2 virus, has been announced as a pandemic by the World Health Organization. COVID-19 has affected people globally, infecting more than 39.8 million people and claiming up to 1.11 million lives, yet there is no effective treatment strategy to cure this disease. As vaccine development is a time-consuming process, currently, efforts are being made to develop alternative plans for the timely and effective management of this disease. Drug repurposing always fascinated researchers and can be utilized as the most acceptable alternative to develop the therapeutics for COVID-19 using the pre-approved drugs. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has shown resemblance with distinctive enzyme targets, such as 3CLpro/Mpro, RdRp, Cathepsin L, and TMPRSS2 present in SARS CoV and MERS CoV. Therefore, the drugs that have shown efficacy in these viruses can also be used for the treatment of COVID-19. This review focuses on why repurposing could provide a better alternative in COVID- 19 treatment. The similarity in the structure and progression of infection of SARS CoV and MERS viruses offers a direction and validation to evaluate the drugs approved for SARS and MERS against COVID-19. It has been indicated that multiple therapeutic options that demonstrate efficacy against SARS CoV 2 are available to mitigate the potential emergence of COVID-19 infection.