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". The patients were hospitalized between December 20, 2019, and April 14, 2020. It found that those who were treated with chloroquine, hydroxychloroquine through four methods all died at a higher rate than those who did not received the drug.
Researchers found the 14,888 patients in the treatment group suffered higher mortality when compared to the control group of over 80,000.
In comparison, only 1 in 11 hospitalised patients from the control group fell victim to coronavirus during this period. That's not what would be expected if the drugs were highly effective treatments. "About 1 in 5 treated with chloroquine and an antibiotic died and nearly 1 in 4 treated with hydroxychloroquine and an antibiotic died". The drug has been tied to unsafe heart rhythm problems.
The study accounted for several "confounding factors", like, age, sex, race or ethnicity, body-mass index. Some proponents of the drugs as treatments for the disease argue that they may need to be administered at an earlier stage in order to be effective.
The estimated excess risk attributable to the drug regimen rather than other factors, such as comorbidities, ranged from 34% to 35%.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, said more research was needed, but added: "A definitive answer still awaits the results of the randomised trials, but it is clear that the drugs should not be given for treatment of Covid-19 other than in the context of a randomised trial".
Those who received Gilead's remdesivir treatment were excluded from the study.
According to the study 8 per cent of the patients treated with hydroxychloroquine and an antibiotic developed a heart arrhythmia.
Malaria drugs pushed by US President Donald Trump as treatments for the coronavirus did not help and were tied to a greater risk of death and heart rhythm problems in a new study of almost 100,000 patients around the world.
"It's one thing not to have benefit, but this shows distinct harm".
The study said there were no benefits to treating patients with the anti-malarial drug hydroxychloroquine. Justification for repurposing these medicines in this way is based on a small number of anecdotal experiences that suggest they may have beneficial effects for people infected with the SARS-CoV-2 virus.
Results from some of the first large, randomized studies of hydroxychloroquine are expected soon, including a study being conducted by the French government and one at the University of Minnesota. "However, we now know from our study that the chance that these medications improve outcomes in COVID-19 is quite low", co-author of the study Dr.
For example, one US study published in late April found the death rate for people with COVID-19 who took hydroxychloroquine on top of usual care was actually higher than those who didn't - 28% vs. 11%, respectively. Frank Ruschitzka, as cited by CNN.
Funding came from Brigham and Women's Hospital in Boston, Massachusetts.