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The Lancet, one of the world’s top medical journals, on Thursday retracted an influential study that raised alarms about the safety of the experimental Covid-19 treatments chloroquine and hydroxychloroquine amid scrutiny of the data underlying the paper.

Just over an hour later, the New England Journal of Medicine retracted a separate study, focused on blood pressure medications in Covid-19, that relied on data from the same company.

The retractions came at the request of the authors of the studies, published last month, who were not directly involved with the data collection and sources, the journals said.


“We can no longer vouch for the veracity of the primary data sources,” Mandeep Mehra of Brigham and Women’s Hospital, Frank Ruschitzka of University Hospital Zurich, and Amit Patel of University of Utah said in a statement issued by the Lancet. “Due to this unfortunate development, the authors request that the paper be retracted.”

The retraction of the Lancet paper is sure to add fuel to contentious arguments about the potential of chloroquine and hydroxychloroquine, two old malaria drugs, in Covid-19, the disease caused by the novel coronavirus. President Trump has touted them as valuable treatments, despite a lack of rigorous data showing they have a benefit.


Meanwhile, on Wednesday, researchers reported the results of the first gold-standard clinical trial of hydroxycholoroquine in Covid-19, concluding that it did not prevent infections any better than placebo. Other clinical trials, including some looking at the drugs as treatments, are ongoing.

The Lancet study gained so much attention because it went further than other observational studies that had similarly found the drugs were not associated with improved outcomes for patients. The study, which was purportedly based on patient data from 671 hospitals on six continents, reported the drugs also corresponded to higher mortality.

The findings led to the pause of some global clinical trials studying hydroxychloroquine so researchers could check for any safety concerns. Outside experts, however, quickly raised concerns after noticing inconsistencies in the data. They asked the company that compiled and analyzed the data, Surgisphere, to explain how it sourced its data.

As scrutiny grew, the authors on the paper not affiliated with Surgisphere called for an independent audit. In their Lancet statement Thursday, they said that Surgisphere was not cooperating with the independent reviewers and would not provide the data.

“As such, 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,” the researchers wrote.

Outside experts raised similar concerns about the New England Journal study, which found that the blood pressure medications were safe to take for people with Covid-19. It was also based on data from Surgisphere.

In the New England Journal retraction statement, the study authors wrote, “Because all the authors were not granted access to the raw data and the raw data could not be made available to a third-party auditor, we are unable to validate the primary data sources underlying our article.” They apologized “for the difficulties that this has caused.”

Concerns about the health risks of chloroquine and hydroxychloroquine were based on evidence beyond the Lancet paper. Earlier, the Food and Drug Administration warned the drugs should not be used in Covid-19 outside a clinical trial or beyond hospitalized patients because of the risks to heart health.

The drugs are safe for people to take for malaria, rheumatoid arthritis, and lupus, for whom they are shown to have benefits, experts stress.

  • In many areas (including NYS), the governor didn’t allow these drugs unless a patient was already hospitalized, practically at a hopeless point. This didn’t allow it to be used to prevent the patient from ever reaching that point of no return. Then they claimed a high mortality rate. That is playing politics with people’s lives. Many who used it earlier recovered with much fewer complications.

  • I do not understand the last 2 sentences. It is like you are saying the drug has side effects only if taken for COVID and no side effects if taken for RA.
    No drug works this way.
    A drug has some side effects period. The drug doesn’t care why are you taking it for.
    It is possible to cause cardiac toxicity if taken for RA too.
    You can argue that benefits outweigh risks in RA while Benefits are not proven in case of COVID. But that it is only causing side effects in case of COVID. This is ridiculous.

    • Agreed, Mahmoud, they could have worded this better. I believe they implicitly meant what you said more explicitly…. that the risk benefit ratio of these medications is justified for auto-immune disorders (SLE, RA) but not, so far, for COVID-19.

  • what’s funny most trump supporters will willfully take the drug knowing it doesn’t show any effects good or bad. BUT baulk at taking vaccines tested for the main purpose to treat the virus…

    • I’m by no stretch a Trump supporter. So do not make the mistake that only people who follow him would be interested in this treatment.
      Because the truth is, I will queue up all day, everyday, to take a medication in use for 50 years. Before I’d roll my sleeve up to take an unproven vaccIne for an RNA virus.
      For your information, there has never before been a successful RNA vaccine been produced. In fact SARS-1 (an RNA virus, closely related) hit the population 17 years ago. Since then there has been research to create a vaccine against it. It has proven unsuccessful in all that time.
      It my mind, it would be a Russian roulette situation to inject whatever they come up with. And now I’ve outlined those facts, I would expect any reasonable person to concur. (After confirming what I’ve said for themselves, at least)

  • If the drug is so potent why aren’t there fewer cases? I know the drug not used everywhere however enough has been used for some kind of effect. and, I don’t believe trump has taken the drug. what people are missing, the drug hasn’t shown any effects one way or the other, so why take medicine just for the sake of taking it. Or to be trumps test tubes…

  • Republicans have used the same weapon against environmental studies – demand identification of subjects when they had been promised confidentiality, then try to nullify pesticide, etc. safety rules based on that study.

  • Are you guys writing deliberately obtuse copy??? Boil it down for those of us who don’t have a degree in obfuscation. I just want to know if the drug is not efficacious or is it actually dangerous. In plain English please.

    • It appears that recent reports that the drugs are not only not efficacious but actually dangerous have been greatly exaggerated. However, the drugs do have well-known side effects, including potentially fatal effects on the heart.

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