Chloroquine

In vitro is one thing, but clinical studies are another, though with relatively few patients yet.

results from more than 100 patients have demonstrated that chloroquine phosphate is superior to the control treatment in inhibiting the exacerbation of pneumonia, improving lung imaging findings, promoting a virus-negative conversion, and shortening the disease course according to the news briefing. ... regulatory authorities and organizers of clinical trials reached an agreement that chloroquine phosphate has potent activity against COVID-19

"Potency" seems like a strong word, but it is probably a term of art here. And I couldn't read the studies to see what they were like and how much "better than control" they were.

I knew chloroquine--used to take it--but I thought it wasn't any use against today's resistant malaria strains, and had no idea it had other uses as well, against other "intracellular infections" such as Q fever and Whipple's disease. And I'd not have thought that a drug effective against intracellular infections by bacteria would also help some viral infections, but the details matter...

Regarding viruses, for reasons probably partly identical involving alkalinisation by chloroquine of the phagolysosome, several studies have shown the effectiveness of this molecule, including against coronaviruses among which is the severe acute respiratory syndrome (SARS)-associated coronavirus

We'll see. It doesn't sound like a cure, but a treatment would be good too. Especially a cheap one like this.

But wait until this replicates before celebrating.

I used to have some pills left over after a bout of malaria over 40 years ago, which I kept around in case of a recurrence--malaria is infamous for those. I think I threw them out decades ago.