Articles being shared on social media make the claim that a study to test the effectiveness of drug chloroquine on coronavirus patients in Brazil was halted after participants developed irregular heart rates and 11 died ( here , here ).

The articles have been flagged multiple times as part of Facebook’s efforts to curb misinformation related to the new coronavirus.

The article and its central claim are true. The findings of the Brazilian team are published online ( here ) and the 11 deaths (out of 81 participants) are shown in table 3 on page 28. The study was indeed halted after deaths were recorded.

Some patients were administered a higher dosage of Chloroquine, while others a lower dosage. Seven deaths were recorded among the patients given a higher dose and four in the lower dosage group. The higher dosage study was halted earlier because it “seemed to be more toxic”, a doctor involved in the study told Reuters.

“Preliminary findings suggest that the higher CQ (chloroquine) dosage (10-day regimen) should not be recommended for COVID-19 treatment because of its potential safety hazards,” their report said.

When asked to elaborate on the study’s findings, the doctor involved said, “All fatalities were on the average of the overall fatality in critically-ill patients, not higher. Patients died because of COVID-19. This disease is very lethal. However, due a trend in higher fatality in the higher dose group, the DSMB decided to stop this group.”

“We still have no data on the efficacy of chloroquine for severe patients with COVID-19”, he added.

As of April 17, the number of patients who had died as part of this study had not changed.

The experiment was reported by publications including USA Today and the New York Times ( here ),( here ).

The claim on social media comes after hydroxychloroquine, an antimalarial drug, was recommended by President Donald Trump to treat the new coronavirus though the treatment is still in testing phases. In an April 4 exclusive, Reuters reported that in mid-March, Trump personally pressed federal health officials to make malaria drugs available to treat the novel coronavirus, though they had been untested against COVID-19, ( here ).

Guidance from the U.S. Centers for Disease Control and Prevention (CDC) as of April 16 states that “Hydroxychloroquine and chloroquine are under investigation in clinical trials for pre-exposure or post-exposure prophylaxis of SARS-CoV-2 infection, and treatment of patients with mild, moderate, and severe COVID-19”, ( here ).

A safe, effective vaccine for the new coronavirus is still more than a year away ( here ). More than 70 vaccine candidates are in development around the world, with at least five in preliminary testing in people.

VERDICT

True: Brazilian chloroquine study on COVID-19 patients was halted after 11 deaths among participants

This article was produced by the Reuters Fact Check team. Read more about our fact checking work here .