Yes, but since 2006, it has not been recommended for use in severe malaria because of problems with resistance, particularly in the Oceania region, according to the World Health Organization.
Although the number of new cases also slowed, Spanish Prime Minister Pedro Sanchez announced an extension of the country's lockdown until April 25.
Hydroxychloroquine tablets are recognised as a prophylactic for those on the front lines of the fight against COVID-19 - doctors, nurses, paramedics, and first responders - and can be used to treat patients.
"It is not clear why hydroxychloroquine is effective at treating autoimmune diseases".
Use of hydroxychloroquine has soared as the United States has quickly become the epicentre of the pandemic, though doctors prescribing it have no idea whether it works.
Are more studies on humans coming?29 million. A lot of drugstores have them, by prescription.
Trump announced during the press conference that the US has secured 29 million doses of hydroxychloroquine.
"This is going to be the hardest and the saddest week of most Americans' lives", Adams said on "Fox News Sunday", comparing it to a modern Pearl Harbour or 9/11 moment.
The president also said that 1.67 million Americans have now been tested and given the results for the virus.
Why does Trump keep touting their benefits?
Experts have not suggested the latter, but Trump is correct that there are promising signs.
While Trump spoke of a "light at the end of the tunnel", Vice President Pence identified "glimmers of hope", and Coronavirus Response Coordinator Deborah Birx said data from Italy was giving the US "hope for what our future could be". It may not work, he said, but he doesn't want to wait 18 months to find out. Americans might be risking their health if they followed Trump's advice to take hydroxychloroquine for a condition for which it's not been tested, argued Dr. James Phillips, professor of emergency medicine at George Washington University hospital. "I think we all know that we have to reach a certain point". Trump has touted the malaria drug hydroxychloroquine in the battle against COVID-19, calling it a "game-changer". Serious side effects or prolonged treatment include liver failure, hearing loss, and muscle paralysis.
Should people just take it and see what happens?They are also used to treat rheumatoid arthritis, lupus, and a few other conditions.
The American Medical Association, the American Pharmacists Association and the American Society of Health-System Pharmacists in a joint statement previously cautioned against "prophylactically prescribing medications now identified as potential treatments for COVID-19".