Dexamethasone, Remdesivir, and monoclonal antibodies are part of the go to treatments for severe Covid cases. They’re the major exotic bits of what they gave trump when he got sick, along with a bunch of over the counter stuff (zinc, vitamin D, melatonin, etc.) My understanding is that the monoclonal antibodies are the really expensive treatments.
The Dexamethasone one is an interesting story. It started out as a more controversial “throw everything at the wall and see what sticks” solution by a specialist who knew steroids well. Later studies have shown a strong effect on survival, so it’s become a fairly uncontroversial part of the tool kit for severe Covid.