On Tuesday, French police searched a Merck plant in Lyon in order to follow up on patient complaints about changes to its thyroid drug Levothyrox. Merck has pledged to help investigators in their search.
The search was carried out by a unit of the national police responsible for public health.
Approximately 3 million French people use Levothyrox, a drug that works as a stand-in for the hormone thyroxine in patients suffering from hypothyroidism.
Merck took lactose away from the drug in March in order to make it easier to tolerate. Lactose was replaced with citric acid and mannitol, which has spurred thousands of patients alleging severe side effects such as memory loss, hair loss, weight gain and palpitations. In September, a prosecutor launched an investigation into whether Merck had deceived patients with the change in formula.
Today, both the old and new formulas are on French store shelves.
Read the Reuters report