Massive New Study Finds Hydroxychloroquine Ineffective, Potentially Deadly

The fierce debate surrounding hydroxychloroquine intensified following the release of the results of a massive study that found that hydroxychloroquine was ineffective at treating COVID-19 and could be deadly to its recipients. 

The study, which was published May 22 in The Lancet, included 96,000 hospitalized COVID-19 patients. Researchers found that patients who were treated with hydroxychloroquine or chloroquine had a significantly greater risk of death (33%) than those who were not. The former group also had a higher risk of developing abnormal heartbeats and going into cardiac arrest.

While hydroxychloroquine is associated with a long list of potential side effects and the FDA has cautioned against its use outside of hospitals due to heart rhythm concerns, the Lancet study was the first to find a higher mortality rate among COVID-19 patients treated with the drug. 

Scientists Question the Validity of the Study

More than 180 scientists from around the world penned an open letter, which was published Thursday, expressing concern about the study’s design and the interpretation of its results, as reported by BuzzFeed News.

In the letter, scientists took issue that raw data was not made available to other researchers, which violates a pledge signed by The Lancet. Other major concerns specified included the fact the average daily doses of hydroxychloroquine given to COVID-19 patients in the study were greater than those recommended by the FDA. 

In response to Thursday’s letter, the team of scientists behind the study corrected some of the data, but emphasized its findings to be the same, according to BuzzFeed News.

Such a response was deemed insufficient by many experts, including James Watson, a Thailand-based statistician with the University of Oxford’s Centre for Tropical Medicine and Global Health, who led the drafting of the letter. Watson stated in an email to BuzzFeed News that the authors did not address the other nine points referred to in the letter.

International Hydroxychloroquine Trials on Hold

Fallout from the release of the study’s results continues. The World Health Organization put enrollment on hold in the hydroxychloroquine group of its Solidarity Trial for COVID-19 treatments. According to Reuters, the WHO is expected to announce today whether it would continue suspending the hydroxychloroquine trials.

French drugmaker Sanofi also announced it was pausing further recruitment of new patients for its clinical trials of hydroxychloroquine for the treatment of COVID-19, CNBC reported. And Nature reported that the United Kingdom’s Medicines and Healthcare Regulatory Agency had halted the majority of the country’s hydroxychloroquine trials for COVID-19.

U.S. Responses to Hydroxychloroquine

On Friday, Senate Minority Leader Chuck Schumer called for the Veterans Affairs Department to release the details and health outcomes for the 1,300 veterans positive for COVID-19 who were prescribed hydroxychloroquine, as reported by Newsday.

And in testimony last week before a House Appropriations subcommittee and as reported by The Washington Post, Veterans Affairs Secretary Robert Wilkie reassured lawmakers that the VA had scaled back its use of hydroxychloroquine to treat COVID-19 in response to results from the Lancet study.


The Lancet study published in May, which suggested a treatment of hydroxychloroquine and chloroquine does not improve coronavirus symptoms and is linked to heart complications and increased risk of death, was retracted on Thursday, June 4. The results of this study led to the World Health Organization pausing its hydroxychloroquine trial, which was later restarted, MHRA in the U.K. pausing recruitment and France halting trials and changing its national recommendation.

When scrutinizing the study, researchers found “both methodological and data integrity concerns,” according to an open letter by clinicians, medical researchers, statisticians and ethicists from across the world. The 10 major concerns outlined in the open letter include an inadequate adjustment for confounding factors, lack of data sharing and no ethics review.

In the retraction, the authors stated, “...our reviewers were not able to conduct an independent and private peer review and therefore notified us of their withdrawal from the peer-review process... Based on this development, we can no longer vouch for the veracity of the primary data sources.”