FDA issues hydroxychloroquine warning as studies show risk in using drug for COVID-19

The anti-malarial drugs hydroxychloroquine and chloroquine were an early contender much touted by President Donald Trump for treating the coronavirus.

But findings in recent studies highlighting the drug’s potentially fatal side effects forced the U.S. Food and Drug Administration’s hand on Friday.

“Hydroxychloroquine and chloroquine have not been shown to be safe and effective for treating or preventing COVID-19,” the FDA said in a notice cautioning against their use outside of hospitals and clinical trials.

“Close supervision is strongly recommended,” the warning states.

FDA’s caution

The FDA said Friday it reviewed case reports from its own “Adverse Event Reporting System” database as well as medical journals and the American Association of Poison Control Centers National Poison Data System and found instances of “serious heart-related adverse events and death” in patients taking hydroxychloroquine and chloroquine.

The drugs were taken alone or in combination with azithromycin — an antibiotic used to treat bacterial infections — or “other QT prolonging medicines,” according to the FDA warning.

QTc invervals are “an indicator of the health of the heart’s electrical recharging system,” NBC reported, citing Dr. Michael Ackerman, a genetic cardiologist. When the QTc is significantly prolonged, patients are at risk for severe cardiac complications — including death.

The FDA is still investigating the safety risks associated with hydroxychloroquine and chloroquine.

In the meantime, the agency said people should not take any form of the drugs not prescribed by a doctor, pointing to accidental poisonings from “mistaken use” of chloroquine — which is also found in fish tank cleaner.

“Be aware that there are no proven treatments for COVID-19 and no vaccine,” the warning states.

The FDA said healthcare professionals should also monitor their patients taking hydroxychloroquine and chloroquine and be aware of the associated risks.

Clinical trial results

There are currently no FDA-approved drugs to treat COVID-19, but hydroxychloroquine and chloroquine have been approved for clinical trials in the U.S. and were issued emergency authorization for use in coronavirus patients without access to a trial.

According to the U.S. National Library of Medicine, its side effects range from mild — such as dizziness, nausea and diarrhea — to severe — including sensitivity to light, bleeding, muscle weakness, hair loss and convulsions.

In extreme cases, the drugs can cause “sudden cardiac death,” NBC News reported.

Hydroxychloroquine treatments in France and Sweden were cut short earlier this month “after reports of severe side effects,” according to Newsweek.

As of April 14, there were at least 142 trials involving chloroquine and hydroxychloroquine, according to the Oxford Centre for Evidence-Based Medicine.

Five have issued reports on their findings — the first two of which have been used to back the use of chloroquine and hydroxychloroquine in COVID-19 patients, CEBM said. The latter three “are all negative.”

Researchers with another study in Brazil released their findings Friday in the peer-reviewed Journal of the American Medical Association, CNBC reported. They had to cut the study short after nearly two dozen patients died from daily dosages of chloroquine.

“We recommend that similar dosages no longer be used for the treatment of severe COVID-19, especially because treatment based on older patients with previous cardiac diseases who are receiving concomitant cardiotoxic drugs should be the rule,” researchers said in the report.