Is hydroxychloroquine a cure for COVID-19?
As COVID-19, the disease caused by the new coronavirus, spreads around the world, researchers have tested old and new treatments to try to find a cure. Hydroxychloroquine, a common malaria drug, has received particular attention.
What is hydroxychloroquine?
Hydroxychloroquine, a safer derivative of chloroquine, is an anti-parasitic and disease-modifying anti-rheumatic drug approved for malaria, lupus and arthritis. The United States Food and Drug Administration initially approved hydroxychloroquine, sold under the brand name Plaquenil, in 1955. Today, Sanofi (NASDAQ: SNY) sells Plaquenil, and dozens of companies, including Pfizer (NYSE: PFE) and Mylan (NASDAQ: MYL), sell hydroxychloroquine under different brands.
In malaria, hydroxychloroquine works by killing the malaria parasites in red blood cells. The use of the drug to treat COVID-19 actually started with research on chloroquine to stop the spread of severe acute respiratory syndrome. The idea is that chloroquine and hydroxychloroquine raise the pH level of an acidic part of the cell membrane, making it more basic, which would interfere with the ability of the virus to enter and replicate in the body.
President Donald Trump touted the benefits of hydroxychloroquine, and in May he said he had taken a two-week treatment as a preventative measure.
Does hydroxychloroquine prevent or treat COVID-19?
Trump’s enthusiasm prompted some to take the drug without a doctor’s approval, resulting in serious health problems and even death. This is why healthcare professionals advise talking to your doctor before taking any prescription medication.
At the end of March, the FDA granted an emergency use authorization for hydroxychloroquine for some patients with COVID-19 but the agency revoked the authorization this week. The FDA has said the known and potential benefits of hydroxychloroquine for COVID-19 no longer outweigh the risks. Yet doctors can continue to prescribe hydroxychloroquine for off-label uses, such as COVID-19, if they see fit.
A small study in Marseille, France earlier this spring first sparked interest in hydroxychloroquine as a possible treatment for COVID-19. Of 14 patients who received hydroxychloroquine only, eight were cured by day six of the study. Out of six patients who received hydroxychloroquine combined with the antibiotic azithromycin, all were cured on the sixth day. Of the 16 people in the control group, who did not receive the treatments, only two patients were free from COVID-19 at that time.
Since this study, other larger trials have shown a lack of efficacy. In the University of Oxford’s Recovery trial, 1,542 patients received hydroxychloroquine, while 3,132 received standard care. After 28 days of treatment, 25.7% of the hydroxychloroquine group and 23.5% of the standard care group died. The study’s chief researchers said the data excluded a significant survival benefit in hospitalized patients.
Another study, published in the New England Journal of Medicine, has shown that hydroxychloroquine does not prevent infection with COVID-19. Of the 821 asymptomatic participants who had been exposed to patients with coronavirus, 11.8% of those who received hydroxychloroquine developed COVID-19 and 14.3% who received placebo developed the disease.
Adding further to the debate, researchers who, in a study published in The Lancet, said they could not confirm the benefits of hydroxychloroquine then retracted the study. There were concerns about “the veracity of the primary data sources,” the authors said.
Despite disappointing test data and the FDA’s decision to revoke the emergency use authorization, interest in hydroxychloroquine remains. There are currently over 100 hydroxychloroquine trials for COVID-19 that are active or recruiting globally.
Is there a cure for COVID-19?
There is no cure for COVID-19 yet, but Gilead Sciences’ (NASDAQ: GILD) remdesivir may be the Best option at present. In May, the FDA granted emergency use authorization for the antiviral in hospitalized patients with severe COVID-19.
In the latest Phase 3 trial data, patients taking remdesivir for five days were 65% more likely to show clinical improvement by day 11 than those in a standard care group. A separate study by the National Institute of Allergy and Infectious Diseases found that remdesivir resulted in faster recovery. Trials also indicate that early treatment with remdesivir produces better results.
Trials with remdesivir are underway to better understand how this antiviral can help most patients get through the coronavirus pandemic.
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