I'm not an expert on pharmacology but that reminds me, a quick check of the headlines shows that the hydroxychloroquine hope has sputtered out. A couple of places (Bahrain and Belgium) reported promising results but everyone else seems to be saying it's a bust.
I doubt that there are any other off-the-shelf, approved drugs with antivirus potential that haven't been tried yet. Remember the hoo-haw about HIV drugs? Seems like a long time ago doesn't it.
I'm pessimistic because this disease is generally cured or kills within a couple of days to a couple of weeks ... effective drugs would presumably either work very quickly, or not at all (in time).
If there is a problem with this disease of very long latency or dormancy (or whatever they call it) like HIV, THEN there may be some existing drugs that work over months or years, but I'm afraid there are no quick fixes in sight.
BTW Covid-19 has a sequence of genes very similar to HIV. Making it a very dangerous little booger. The question of how and where that chunk of its DNA um, evolved, is an interesting one that has not been answered ...