The mean age of patients was 54 years old and 53% were men. Those who were on mechanical ventilators or who received remdesivir, an antiviral drug made by Gilead Sciences that has shown promise in decreasing recovery times, were excluded.
Healthcare workers in the United Kingdom will begin taking hydroxychloroquine on Thursday as part of a trial to test the drug's efficacy in preventing COVID-19.
The researchers acknowledged observational studies can not account for unmeasured confounding factors but added, "our findings suggest not only an absence of therapeutic benefit but also potential harm with the use of hydroxychloroquine or chloroquine drug regimens (with or without a macrolide) in hospitalized patients with COVID-19".
Trump's White House physician later released a statement, saying that the "benefit outweighed the potential risks" of the drug.
One in six of those taking one of the drugs died, while one in five died if they were taking chloroquine with an antibiotic, and one in four if they were on hydroxychloroquine and an antibiotic. A NY study similarly found hydroxychloroquine did not lower the risk of dying or needing a breathing tube.
Magrini says while the drug was being used in Italy, the agency recommended it only in some patients, preferably on its own or in association with other drugs only in clinical trial settings.
One of the findings of the current study seems hard to ignore: that the drugs increase the risk of risky disturbances in heart rhythms. "Based upon these findings and others, no one should take hydroxychloroquine with or without an antibiotic unless they are in a randomized controlled trial".
It has not yet been shown to be safe and effective in the prevention or treatment of coronavirus and can cause risky heart arrhythmias.
But those findings of safety were at lower doses than were being used at hospitals during the early days of the surge in patients in the United States and mostly in patients who were healthy.
The FDA also warned that "hydroxychloroquine and chloroquine can cause abnormal heart rhythms".
There is a frantic search for drugs to treat people who have become ill with Covid-19, while research teams around the world also pursue a safe and effective vaccine to combat the virus. "I'm on the hydroxychloroquine.' They were like, 'Well, nobody ever said that was the cure or that was going to keep you safe" and it definitely did not".