Download App
The largest observational study yet on the effect of hydroxychloroquine treatment for COVID-19 has cast serious doubts on the safety and therapeutic action of the drug for severely ill and hospitalised COVID-19 patients.
The study, which looked at over 96,000 patients across the world from last December to April, found that those on hydroxychloroquine had a significantly higher risk of death than those on placebo treatment.
Further, researchers found that when hydroxychloroquine was used with an antibiotic cocktail, the likelihood of irregular heartbeat (arrhythmia) increased even more, leading to a higher chance of cardiac failure.
The study also failed to find any beneficial effects of the drug. Hydroxychloroquine, and chemically similar chloroquine, had been granted emergency use approval from the US Food and Drug Administration following lab studies that showed that they counter the coronavirus (SARS-CoV-2) that causes COVID-19.
This study adds to mounting evidence that hydroxychloroquine can have adverse effects in high doses and does little to protect against the disease.
What was the structure of the study?
This was an observational study, meaning that it wasn’t controlled and the health outcomes of the patients were looked at retrospectively. This means it can’t be said that hydroxychloroquine caused the deaths—however, the sheer size of the study has worried doctors and researchers alike.
Out of the 96,000 people in the study, 14,888 had been given hydroxychloroquine or chloroquine with or without the antibiotic cocktail. Those who were on ventilator support or on other experimental treatment, such as the drug Remdesivir for COVID-19 treatment, were not included in the study. The average age of participants was 54, and 53% of the patients were male.
(Read more: COVID-19 patients and ventilators.)
What were the findings?
Patients who were given just hydroxychloroquine saw a 34% increase in the risk of mortality and a 137% increase in the risk of severe arrhythmias. For those given the drug along with the antibiotic cocktail, the risk of death increased by 45% and the risk of serious arrhythmias increased by 411%. For those who were given chloroquine along with an antibiotic, there was a 37% increase in the risk of death and a 301% increase in the risk of serious arrhythmias.
Again, since this was not a controlled study, the condition of the patients beforehand was not known and there are many confounders that could at least in part contribute to the findings.
However, following the release of the report, which was published in The Lancet on 22 May, many researchers have requested the FDA to remove emergency approval and have said the drugs should not be given to patients unless it is for a study. The US National Institutes of Health (NIH) has planned a randomized control study for next week on hydroxychloroquine which will shed more light on the safety and effectiveness of the drug.
The situation in India
The Indian Council of Medical Research (ICMR) on 21 May released an advisory recommending hydroxychloroquine as a prophylactic for at-risk populations like asymptomatic healthcare workers in non-COVID and COVID hospital blocks, frontline workers managing containment zones as well as police forces managing the COVID-19 related activities.
The advisory is based on an NIV (National Institute of Virology) report that showed in vitro (test tube) action of the drug against the virus.
The advisory panel also cited another study with over 1,300 participants that showed that people who were given hydroxychloroquine as a preventive measure (prophylaxis), had mild side effects such as nausea and vomiting and abdominal pain. A small percentage, 1.9%, had cardiovascular effects. They also cited other small observational studies that showed that hydroxychloroquine has a prophylactic effect.
Children under 15 cannot be given the drug, and neither can those with cardiovascular issues. Further, according to the ICMR advisory, a physician should provide the drug and dosage, and if there are adverse side effects, the drug must be stopped.
(Read more: Children and COVID-19: The latest research)
More studies are underway to check for the usefulness of hydroxychloroquine as a prophylactic and for treatment in the early stages of COVID-19, though. The findings of one such research, done at the University of Minnesota, US, may be published before the end of the month.
It remains to be seen if The Lancet study will have an impact on this advisory. Evidence on the prophylactic effect of HCQ remains scant. An analysis comparing 2,354 participants who were given the drug versus 1,952 controls who were not, found no significant differences in their health outcomes as a result of COVID-19.
