Death threats against authors of chloroquine trial


  • Dawn O'Shea
  • Univadis Medical News
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The Brazilian researchers behind the COVID-19 chloroquine trial have received death threats following publication of the negative results, the Lancet reports.

The study, the first randomised controlled trial of chloroquine for severe COVID-19, raised red flags about the high-dosage regimen (12g during 10 days), concluding that the risks of toxic effects outweighed the benefits.

The unfavourable outcome provoked animosity towards the researchers. There were accusations that the trial was “a left-wing funded study that intentionally administered extremely high doses and used a less-safe version of the drug hydroxychloroquine, then used this as a pretence to indicate that chloroquine was ineffective and dangerous”. The Brazilian president's son called it “a fake study aimed at demonising the drug” and called for an investigation.

Three public prosecutors in Brazil have now launched legal proceedings against the authors, particularly in relation to the high dose used, the use of chloroquine instead of hydroxychloroquine, and the patient population.

Speaking to the Lancet Infectious Diseases, principal investigator Marcus Lacerda, said: “When we first announced we were going to test chloroquine to treat COVID-19 we were seen as heroes in Brazil, people sent us encouraging messages and everyone was excited. However, when the study's results came out, the attitude changed." He said he is still in disbelief.