The well-tolerated drug niclosamide, used for treating tape worm parasites, has shown good promise at inhibiting the COVID-19 virus replication within a host cell.
A tapeworm drug against SARS-CoV-2? (Science Daily, June 21, 2021)
Of course, this is just testing with cultured cells. It is undergoing a trial on COVID-19-infected people at Charité in Germany.