What We Don’t Know

Whether the drugs are effective at treating the coronavirus.

One small study in France seemed to suggest that hydroxychloroquine, combined with azithromycin, could work as a treatment for COVID-19. A different small study out of China suggests that hydroxychloroquine was not effective in patients compared with those who did not get the medication.

“I think this is an example where the speed of the virus is moving faster than the speed of the evidence,” Joel F. Farley, a professor at the University of Minnesota College of Pharmacy, wrote in an email to ProPublica.

Juurlink of the University of Toronto said he supports the use of the drugs in patients with serious illness but not those with mild symptoms or to try to keep people from getting infected.

“I might have a completely different answer a month or two from now once we have better data,” he said. “I have no idea whether the advice I’m giving you is good or not, but it’s the best I can come up with as of March 27.”