Levothyrox thyroid drug: Old formula available in France until 2025

The old formula of the thyroid drug Levothyrox, whose formula was controversially changed in 2017, will now be available in France until 2025.

The decision followed a request from France’s medicines safety agency l’Agence nationale de sécurité du médicament et des produits de santé (ANSM), said drug manufacturer Merck KGaA to the Agence France-Presse on Tuesday (September 5).

Patient campaign group l'Association Française des Malades de la Thyroïde (AFMT) told Le Monde that the decision was an “immense relief” for “the 100,000 or so patients who continue to use” Levothyrox everyday, and “feared [the old formula] would disappear”.

Read more: New France-UK study finds Levothyrox ‘not equivalent’

Old formula imports

However, the old formula will only be available until 2025.

As a result, Merck has highlighted “the need for healthcare professionals to support patients in finding long-lasting treatment that supports them the best, so as to be prepared for when this old formula will no longer be available at all”.

It added that the old formula is being temporarily imported into France from “batches intended for the last countries which have not yet changed over to the new formula”.

These batches are “manufactured in exactly the same way as the old Levothyrox, in Germany”, it said, and added that current batches had initially been destined for Argentina, and further supplies would be from batches originally intended for the Russian market.

Merck had been set to stop importing the old Levothyrox formula to France in 2020, but this date has been extended several times.

Read more: Old Levothyrox formula available in France until end of 2021

Read more: Minister brings back old Levothyrox as crisis grows

Drug ‘not equivalent’?

The company is facing lawsuits about the new Levothyrox formula, which uses the same active ingredient - levothyroxine - but uses different excipients (inactive substances), for example, it changes lactose for mannitol and citric acid.

When the new formula first replaced the old version, between March 2017 and April 2018, around 31,000 patients reported headaches, insomnia, vertigo and other side effects - including the return of their thyroid symptoms - leading them to question the composition of the new formula.

Levothyrox was the most-used treatment option in France for patients suffering from underactive thyroid function and other thyroid conditions, which can cause weight gain, depression, circulation problems, coldness, and extreme fatigue.

Other drugs are now used, but thousands of patients still take Levothyrox every day.

The company and ANSM are facing charges of “aggravated deception” as a result, for allegedly not communicating clearly to patients the change in formula.

Independent tests on the new formula showed that it is identical to the old in terms of active ingredients - and in 2018, the ANSM confirmed the “good quality” of the drug - but thousands of patients have claimed that it is not effective, and one French-UK study found that the medicines were “not equivalent”.

Read more: New France-UK study finds Levothyrox 'not equivalent'

A €3.3 million ‘fault’

In March 2022, Merck was ordered to pay €3.3m to more than 3,300 Levothyrox victims, after the highest French court, la Cour de cassation, said that the pharmaceutical giant had committed “a fault”.

It said: “When the composition of a medicine changes and this change in formula is not explicitly indicated in the package leaflet, the manufacturer and the operator may be reproached for a lack of information…which may ‘cause damage’ to a person’s quality of life.”

An inquiry into the issue even included the charge of manslaughter, after lawyers said that a “woman connected to the case” had died.

Read also

Levothyrox France: National medicines agency investigated

Levothyrox controversy in France: Merck indicted for ‘deception’