File pic: First consignment of HCQ tablets from India in Canada
Washington DC, May 17, 2020: Clinical trials of the anti-malarial drug or hydroxychloroquine, which gained prominence overnight after being promoted by US President Donald Trump as a 'game changer' in the fight against Covid-19, have been significantly linked to cardiac problems and increased risk of death for certain patients.
More than 27 percent of patients treated with hydroxychloroquine died, and 22 percent of those treated with the combination (chloroquine and hydroxychloroquine) therapy died, compared with an 11.4 percent death rate in those not treated with the drugs, the study said.
Evidence showing the ineffectiveness of hydroxychloroquine in treating covid-19 has been scant, so much so that the Food and Drug Administration (FDA) warned against its usage outside of a hospital setting, last month, just weeks after it approved an emergency use authorisation for the drug, The Washington Post reported.
Some drug safety experts are now calling for even more forceful action by the government to discourage its use. Several have called for the FDA to revoke its emergency use authorization, given hydroxychloroquine's documented risks.
"They should say, 'We know there are harms, and until we know the benefits, let's hold off,' " Joseph Ross, a professor of medicine and public health at Yale University, told the Post, and added that the original authorisation may have been warranted but new evidence has emerged about the drug's risks.
"I'm surprised it hasn't been revoked yet," said Luciana Borio, who served as director for medical and biodefense preparedness of the National Security Council and was acting chief scientist at the FDA.
Testimony before the Congress on Thursday from Rick Bright, a former top vaccine official, who was removed from his post last month, further highlighted allegations that Trump's White House pressured government scientists to quickly sign off on the untested drug in March, at the same time the president was pitching it as a "game changer."
In his whistleblower complaint, Bright said he was removed from his position in part because of his reluctance to promote the use of chloroquine and hydroxychloroquine, because they had not been tested and deemed safe for treating covid-19.
"It's important to use available clinical data," Bright told lawmakers.
"And if we know there are potential risks, we need to make sure that we are cognizant of those risks and make sure those drugs are used in a very safe and controlled manner," he said further.
However, Health and Human Services Secretary Alex Azar attacked Bright on Thursday, saying "his allegations do not hold water."
The FDA said in a statement on Friday that it is continuing to evaluate its emergency use authorization for chloroquine and hydroxychloroquine, as it does with all such authorizations for drugs to ensure their continued safety.
"In general, the FDA may revise or revoke an EUA under certain circumstances, including information related to linked or suspected adverse events, newly emerging data that may contribute to revision of the FDA's initial conclusion that a product may be effective against the particular threat or a material change in the risk/benefit assessment based on evolving understanding of the disease or condition," the statement said.
Trump has continued to promote hydroxychloroquine without reservation while attacking those who question its effectiveness. He has also described Bright as a "disgruntled employee" who is resisting the proposed treatment without cause.
But doctors, health experts and officials from Trump's own administration say the evidence does not back up the president's positive assertions. Those assertions, which Trump has claimed are partly based on "a feeling," could be costing lives, they said.
Yogen Kanthi, assistant professor in the division of cardiovascular medicine at the University of Michigan, was quoted by the Post saying it has been clear that the combination of hydroxychloroquine and azithromycin -- used to treat bacterial infections -- could lead to cardiac arrhythmias, which cause the heart to beat irregularly or too fast or slow. Many patients hospitalized for covid-19 had underlying cardiovascular disease that put them at higher risk for arrhythmias, "so it shouldn't be surprising we saw an increase in death," he said.
In addition, a study of Veterans Affairs patients hospitalised with the coronavirus found no benefit and higher death rates among those taking the drug, researchers said last month.
While hydroxychloroquine is approved by the FDA to treat malaria, rheumatoid arthritis and lupus, some medical groups have long voiced concern that using it for coronavirus patients was particularly risky.
Doctors in Brazil stopped a trial of chloroquine, closely related to hydroxychloroquine, after 11 patients died. They reported in JAMA Open Network on April 24 that in 81 patients, those who took high doses of the drug had a 3.6-fold higher death rate as compared to a lower dose group.
Brazil's top health official resigned Friday following reported disagreements with President Jair Bolsonaro over the efficacy of the anti-malarial drug in curbing the rapid rise of coronavirus in Latin America's largest country.