On Monday, the Federal Drug Administration in the US revoked its emergency approval of the controversial malaria drugs, hydroxychloroquine and chloroquine, for treating COVID-19, stating that the drugs are unlikely to be effective in treating the respiratory infection caused by the novel coronavirus (Sars-CoV-2).
In a statement, the agency said: “FDA has determined that CQ and HCQ are unlikely to be effective in treating COVID-19 for the authorized uses in the EUA. Additionally, in light of ongoing serious cardiac adverse events and other serious side effects, the known and potential benefits of CQ and HCQ no longer outweigh the known and potential risks for the authorized use”.
Indeed, over the past few weeks, research has emerged showing that the drug, which was granted emergency approval by the FDA in late March, is not effective in treating Covid-19 or preventing the respiratory disease from developing in those exposed to the virus.
To date, the science behind hydroxychloroquine use has been unreliable, to say the least. Just last week, The Lancet and the New England Journal of Medicine, two leading medical journals, retracted papers after expressions of concern by some authors over the validity of the data.
So far, no large rigorous studies have been able to show the drugs are safe or effective for preventing or treating Covid-19. In fact, a number of recent studies seem to suggest hydroxychloroquine could do more harm than good. The drug can cause arrhythmia, severely low blood pressure, muscle or nerve damage, and serious heart problems, according to more than 390 reports of complications.
Despite the lack of reliable evidence supporting its effectiveness in treating or preventing Covid-19, President Donald Trump has continued to promote the drug. Instead, his belief is backed by ‘just a feeling’, he said at a press conference last month. The US president claims to have himself taken the drugs preventively after two white house employees were diagnosed with the virus. Trump has urged others to try it, which has led to a surge in prescriptions and subsequent shortages in the malaria drugs, which are needed for other indications.
The repurposing of drugs is not unusual. While originally for malaria in 1955, hydroxychloroquine and chloroquine have also been frequently prescribed for decades to treat lupus and rheumatoid arthritis. The withdrawal does not necessarily mean the drugs can no longer be used in clinical trials, researchers are debating whether to halt ongoing trials.
Meanwhile, health experts including Anthony Fauci have cautioned against its use for treating or preventing COVID-19 since there is no reliable evidence supporting its use. Dr Steven Nissen, a researcher at the Cleveland Clinic and frequent FDA adviser agrees with the latest FDA decision and told the Guardian: “There has never been any high-quality evidence suggesting that hydroxychloroquine is effective” for treating or preventing coronavirus infection.
In a separate statement, the FDA also warned against the use of the anti-malaria drugs alongside remdesivir, another promising candidate for treating COVID-19 infection, stating hydroxychloroquine might actually reduce the effectiveness of remdesivir. The drug, made by Gilead, was granted emergency approval last month. Remdesivir is now the only drug with FDA authorization against Covid-19.