The French unit of German pharmaceuticals firm Merck has been charged with willful commercial deception for failing to inform patients of changes to a thyroid treatment that could result in serious side-effects.
A court in 2020 ordered the company to pay compensation to more than 3,300 plaintiffs in a civil hearing of the same charges. An appeal against that ruling was rejected by France's supreme court earlier this year.
Some 30,000 people in France reported suffering headaches, insomnia, hair loss or dizziness after taking a new version of Levothyrox, a drug used to treat underactive thyroid glands or following surgery for cancer of the organ, which regulates the body's metabolism.
France is the world's biggest consumer of Levothyrox, with around 2.5 million users according to Merck, and was the first country where the new version of the drug was introduced in 2017.
The patients claim that Merck did not adequately inform them of the changes or the potential for additional side effects. A petition urging a return to the old formula has collected some 170,000 signatures.
Merck France said its president was questioned by an investigating magistrate in the southern city of Marseille on Tuesday, after which the charges were filed.
"This case in no way concerns the quality of the new Levothyrox formula," the company said, adding that it would provide "all necessary information to show there was no criminal fault of any kind".
In the civil case, judges ordered Merck to pay each of the 3,329 parties 1,000 euros. The plaintiffs had asked for ten times that amount.
After its introduction in France, the new form of the drug was made available in two dozen other European countries, without any problems, according to Merck.
The company claims that side effects are "normal and comparable to the old" formula.
(With AFP)