Nearly 17,000 people may have died after taking hydroxycholoroquine during the first wave of COVID, according to a study by French researchers.

The anti-malaria drug was prescribed to some patients hospitalized with COVID-19 during the first wave of the pandemic, “despite the absence of evidence documenting its clinical benefits,” the researchers point out in their paper, published in the February issue of Biomedicine & Pharmacotherapy.

Now, researchers have estimated that some 16,990 people in six countries — France, Belgium, Italy, Spain, Turkey and the U.S. — may have died as a result.

That figure stems from a study published in the Nature scientific journal in 2021 which reported an 11 percent increase in the mortality rate, linked to its prescription against COVID-19, because of the potential adverse effects like heart rhythm disorders, and its use instead of other effective treatments.

Researchers from universities in Lyon, France, and Québec, Canada, used that figure to analyze hospitalization data for COVID in each of the six countries, exposure to hydroxychloroquine and the increase in the relative risk of death linked to the drug.

In fact, they say the figure may be far higher given the study only concerns six countries from March to July 2020, when the drug was prescribed much more widely.

Hydroxychloroquine gained prominence partly due to French virologist Didier Raoult who had headed the Méditerranée Infection Foundation hospital, but was later removed amid growing controversy.

It was also considered something of a “miracle cure” by the then-U.S. President Donald Trump, who said: “What do you have to lose? Take it.”