Anti-malaria drug hydroxychloroquine fails another test as a Covid-19 treatment, says study
Anti-malaria drug hydroxychloroquine has failed another test to check its efficacy in treating the coronavirus disease (Covid-19), a new study has revealed, with patients admitted to hospitals showing no change in their conditions after being administered the medicine.
The observational study published in the highly cited New England Journal of Medicine (NEJM) showed that doctors reported that the use of hydroxycholoquine neither lessened the need for patients requiring breathing assistance nor the risk of death.
The study said there were no potential benefits or harm from the drug, which was given to 1,376 consecutive patients in the emergency room with Covid-19 symptoms in the New York-Presbyterian Hospital and Columbia University Irving Medical Center in New York City.
The NEJM study found that the risk of intubation or death was not significantly higher or lower among consecutive patients who were given hydroxychloroquine compared to those who were not given the drug. “There was no significant association between hydroxychloroquine use and intubation or death,” the study concluded.
The findings come two weeks after the US Food and Drug Administration warned the public against using hydroxychloroquine and chloroquine without prescription or supervision because of reports of “serious heart rhythm problems” in patients treated with the malaria drugs.
“There is still no convincing evidence for treatment. To rule out unmeasured confounding and bias, randomised-control trial evidence in larger numbers is needed, such as from multi-country solidarity trial being conducted by World Health Organization,” said Dr K Srinath Reddy, president, Public Health Foundation of India. India is among the countries testing the safety and efficacy of hydroxychloroquine as part of the solidarity trial.
Observational studies aren’t considered as conclusive as randomised-controlled trials because clinicians often use several drugs and therapies to treat patients. More rigorous clinical trials are needed to establish the effectiveness of the drug, said the NEJM study, which was funded by the US National Institutes of Health.
Hydroxychloroquine is the only drug approved for treating hospitalised Covid-19 patients in India, where it is given in combination with the antibiotic azithromycin. It is also being given to health care workers and people at risk of exposure as a prophylaxis for Covid-19, which leads to potentially fatal complications in some patients.
The cheap and widely available drug that has been used to treat malaria for at least a century emerged as the most sought-after medicine after two preliminary trials in Covid-19 patients in China in March showed it boosted recovery and lowered the severity of Covid-19.
An early study from France also showed benefit of hydroxychloroquine in 26 patients treated at French hospitals, but flaws in study design made it difficult to interpret. The studies were published in medRxiv, a pre-print website that publishes studies before peer-review to expedite access to new research.
An analysis published in the journal Annals of Internal Medicine in March, however, said the “data to support the use of hydroxychloroquine and chloroquine are limited and inconclusive.”
Apart from malaria, hydroxychloroquine is prescribed for rheumatoid arthritis and lupus. Several countries including India, China, France, South Korea, Italy, India and the United States are using anti-malarials to treat people severely ill with Covid-19.
US President Donald Trump has touted the drug as a “game changer” in the fight against Covid-19.
Anti-malarials work by decreasing the acidity in endosomes, which are compartments within cells that some viruses hijack to enter the cell and cause infection. The doorway used by Sars-Cov-2 is the spike protein on its surface that it uses to attach to a receptor on the surface of human cells, but studies in cell culture have suggested chloroquines have some activity against the virus.
The doses needed to treat Covid-19 are usually very high, which raises risk of toxicities, which led a small study in Brazil being suspended after researchers found high doses led to irregular heartbeats (heart arrhythmia).
Last week, Gilead Sciences’ antiviral drug remdesivir became the first drug to get emergency use authorisation in the US for treatment of Covid-19. The move came after the US National Institute of Allergy and Infectious Diseases released results from its study showing Covid-19 patients who took remdesivir usually recovered after 11 days, four days faster than those who didn’t take the drug.