https://www.wired.com/story/an-old-malaria-drug-may-fight-covid-19-and-silicon-valleys-into-it/

The chatter about a promising drug to fight Covid-19 started, as chatter often does (but science does not), on Twitter. A blockchain investor named James Todaro tweeted that an 85-year-old malaria drug called chloroquine was a potential treatment and preventative against the disease caused by the new coronavirus. Todaro linked to a Google doc he’d cowritten, explaining the idea.

Though nearly a dozen drugs to treat coronavirus are in clinical trials in China, just one—remdesivir, an antiviral that was in trials against Ebola and the coronavirus MERS—is in full-on trials in the US. Nothing has been approved by the Food and Drug Administration. So a promising drug would be great—and even better, chloroquine isn’t new. Its use dates back to World War II, and it’s derived from the bark of the chinchona tree, like quinine, a centuries-old antimalarial. That means the drug is now generic and is relatively cheap. Physicians understand it well, and they’re allowed to prescribe it for anything they want, not just malaria.