Chloroquine, a malaria treatment discovered during the 1930s, and a newer, related drug, hydroxychloroquine, have officially been authorized in the U.S. for emergency use against the novel coronavirus. 

The Food and Drug Administration hasn't formally approved chloroquine and hydroxychloroquine for the treatment of COVID-19. Instead, it granted an emergency-use authorization (EUA) that allows them to be given to hospitalized coronavirus patients who can't participate in clinical trials of the drugs. 

An approving doctor in a hospital room.

Image source: Getty Images.

Healthcare providers didn't have to wait for the EUA to attempt to treat COVID-19 patients with chloroquine or hydroxychloroquine, but the Biomedical Advanced Research and Development Authority (BARDA) needed that authorization before it could distribute those donated drugs. Some of the world's largest pharmaceutical companies, including Novartis (NYSE:NVS), and Teva Pharmaceutical (NYSE:TEVA) have already committed to donating the drugs.

Still unproven

The FDA thinks it's reasonable to conclude chloroquine-based treatments might be effective against COVID-19 based largely on the results of a study with some significant flaws. An impressive 78 out of 80 COVID-19 patients treated with a combination of hydroxychloroquine and azithromycin tested negative for the novel coronavirus five days after starting treatment.

Compared to reports from Chinese researchers, reducing the viral load for that many people in five days is remarkable. Unfortunately, we don't have any data from a placebo group, so it's hard to tell if the hydroxychloroquine was the reason they improved or if the hospital just got really lucky.

Controlled clinical trials with patients randomly placed in groups receiving chloroquine or hydroxychloroquine or placeboes are underway, and they should produce meaningful results that support or disprove the drugs' potential to treat COVID-19 before the end of April.