Selection of "parent" drugs already considered for COVID-19 treatment. An extensive literature search for approved drugs that have shown therapeutic potential against COVID-19 resulted in 71 hits, of which 29 are currently being tested in clinical trials and 42 exhibited some activity in in vitro studies. This collection, along with pertinent literature references, is detailed in the Supplementary Information, Table . In the following, the selected drugs are referred to as "parents".