Chloroquine or hydroxychloroquine (HCQ), with or without an antibiotic, in hospitalized COVID-19 patients were associated with increased risk of death in the hospital and higher rates of arrhythmias, analysis of outcomes in almost 100,000 patients indicated.
David Maron, director of preventive cardiology at the Stanford University School of Medicine, said that "these findings provide absolutely no reason for optimism that these drugs might be useful in the prevention or treatment of COVID-19". The paper had been posted online May 11 and hadn't been reviewed or published in a medical journal.
Hydroxychloroquine is a prescription drug used for acute malaria and certain types of arthritis.
It can reduce inflammation, pain, and swelling - and is widely used to treat rheumatic diseases. People sick enough to be hospitalized with the coronavirus are not the same as healthy people taking the drugs in other situations, so safety can not be assumed from prior use, Mehra said.
About 9% of patients taking none of the drugs died in the hospital, versus 16% on chloroquine, 18% on hydroxychloroquine, 22% on chloroquine plus an antibiotic, and 24% on hydroxychloroquine plus an antibiotic.
The death rate among all groups taking the drugs was higher than among people who were not given them. This combination is one President Trump has been encouraging.
"If there was ever hope for this drug, this is the death of it", said Topol.
The statistics are not exactly comparable because, as this was not a trial, there were differences in the age, gender, general health and stage of illness of the patients. But the United States authors of the study say, allowing for these differences, there was still higher mortality among those taking the drugs. And for those who received hydroxychloroquine and an antibiotic, there was a 45% increased risk of death and a 411% increased risk of serious heart arrhythmias.
The Lancet study looked at data from 671 hospitals, where 14,888 patients were given either hydroxychloroquine or chloroquine, with or without the antibiotic macrolide, and 81,144 patients who were not treated with those drugs.
"Our findings suggest not only an absence of therapeutic benefit but also potential harm with the use of hydroxychloroquine or chloroquine drug regimens ... in hospitalized patients with COVID-19".
Doctors have also argued it could be unsafe to take if people don't have a condition the drug is created to help. Previous trials studied the drug as a possible treatment for COVID-19.
British health workers are to take part in the first global study involving hydroxychloroquine - the drug US President Donald Trump revealed he was taking as a preventive measure against COVID-19, reported Sky News.
Dr Stephen Griffin, associate professor in the school of medicine at the University of Leeds, called for more research but said: "This is potentially a landmark study for Covid-19 therapy".
At the end of the study period around nine per cent of those in the control group had died.
There was also a control group of patients not given these treatments.