Clinical Efficacy and Safety of Antiviral Drugs in the Extended Use against COVID-19: What We Know So Far

Human beings around the globe have been suffering from a devastating novel pandemic and public health emergency, coronavirus disease 2019 (COVID-19), for more than one and a half years due to the deadly and highly pathogenic severe acute respiratory coronavirus 2 (SARS-CoV-2) infection worldwide. Notably, no effective treatment strategy has been approved for the complete recovery of COVID-19 patients, though several vaccines have been rolled out around the world upon emergency use authorization. After the emergence of the COVID-19 outbreak globally, plenty of clinical investigations commenced to screen the safety and efficacy of several previously approved drugs to be repurposed against the SARS-CoV-2 pathogen. This concise review aims at exploring the current status of the clinical efficacy and safety profile of several antiviral medications for the treatment of patients with COVID-19 and other respiratory complications caused by SARS-CoV-2 infection. The paper covers all kinds of human studies (January 2020 to June 2021) except case reports/series to highlight the clear conclusion based on the current clinical evidence. Among the promising repositioned antivirals, remdesivir has been recommended in critical conditions to mitigate the fatality rate and improve clinical conditions. In addition, boosting the immune system is believed to be beneficial in treating COVID-19 patients, so interferon type I might exert immunomodulation through its antiviral effects by stimulating interferon-stimulated gene (ISG). However, more extensive clinical studies covering all ethnic groups globally are warranted based on current data to better understand the clinical efficacy of the currently proposed repurposed drugs against COVID-19.