Repurposing Existing Drugs for the Treatment of COVID-19

The rapid global spread and significant mortality associated with the coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral infection has spurred an urgent race to find effective treatments. Repurposing existing drugs is a particularly attractive approach as pharmacokinetic and safety data already exist; thus, development can leapfrog straight to clinical trials of efficacy, generating results far more quickly than de novo drug development. This review summarizes the state of play for the principle drugs identified as candidates to be repurposed for treating COVID-19 grouped by broad mechanism of action: antiviral, immune enhancing, and antiinflammatory or immunomodulatory. Patient selection, particularly with regard to disease stage, is likely to be key. To date, only dexamethasone and remdesivir have been shown to be effective, but several other promising candidates are in trials.