They have done limited studies on hydroxychloroquine or Plaquinil, There are some clinical trials that have started. I believe they are using Azithromycin with it. They are using high dose. There are also trials on the anti-malaria drug Chloroquine. The dose is different for both and they are not the same drug. So far they are only using Plaquinil on the very ill since the side effects can be very harsh. Some get very low platelets and bleed and you can get retinal toxicity and go blind. But I think in the short term dosage it may be okay but there is no data to prove one way or the other that I know of. I do know my friend lost her eye sight due to Plaquinil. She was being closely monitored by an eye specialist and she was on long term (years) of Plaquinil. But another friend of mine was on it for a short time. About a month or maybe two and she got bleeding through the mouth. So you don't want to take it without the advise of a physician.
France study says no effect on people who took it within 48 hours of hospitalization. https://www.cnn.com/2020/04/15/health/new-french-study-hydroxychloroquine/index.html
More study data coming next week.
Also this reporter interviewed some doctors in NY hospitals;
"...hydroxychloroquine, the anti-malaria medication that President Trump has hailed as a possible “game changer.” Most patients at both hospitals I visited have been receiving hydroxychloroquine, sometimes combined with the drug azithromycin, but people are still dying in large numbers. Some doctors think that these drugs help if administered early, but I spoke to no one on the front lines who believed they were a game changer."
There are different studies some say it works and for some, it doesn't. Hydroxychloroquine has helped some patients and it gives relives that why everyone is looking for it and trying to get the best result from it.