A former researcher at the Merck laboratory - which manufactures and markets Levothyrox - believes that citric acid, present in the new formula of treatment, would affect its effectiveness and would be the cause of adverse effects.
While doctors have recently discovered metal nanoparticles in the new formula of Levothyrox, which could explain the side effects felt by patients, a researcher in pharmacy estimates that citric acid, present in large quantities, decrease the effectiveness of the drug. treatment.
A former researcher at Merck Lab - who makes and markets the drug - thinks that might be the case. "Citric acid is a powerful acid that is in large quantities, so it's obvious that there is a chemical reaction. (...) An amount such that we will have a degradation of thyroxine. The active ingredient will be in acid form, inactive. This is the basic chemistry of the first year of pharmacy ... ", he said on condition of anonymity on France Info.
In sum, citric acid neutralizes part of the active molecule of Levothyrox. "There are a lot of doctors who do not know the drug because they have never studied it, but they are the ones we hear," said the scientist, "we heard that citric acid was very good. Yes, but there is no levothyroxine in chewing gum ... "According to him, the Merk lab would have gone too fast to make a patent, because the molecule falls into the public domain in 2019 ".
Dr. Amine Umlil, who has been making drugs all his life and now works on his own, contacted Mr. Christophe Lèguevaques, a lawyer who defends hundreds of people involved in the return of the old formula of Levothyrox. In his book his volume II Know the medicine, the scientist writes "It is admitted that lime, like grapefruit, has an enzymatic inhibitory effect. (...) The elimination of levothyroxine would thus be curbed, which would lead to an accumulation of the drug in the body. . "
Between 3000 and 5000 patients soon in procedure
The case of Levothyrox was born of the change of formula, last July, when thousands of patients began to complain about undesirable side effects. In total, more than 17,000 cases were reported to ANSM on 2.3 million patients treated in France. The link with the change of formula was mentioned and a vast administrative inquiry was launched while the pharmacologists are hard to explain such a crisis. Last October 24, however, Christophe Lèguevaques brought the Merck laboratory to justice and filed the first 108 cases, ensuring that 2,000 others are waiting to be. In total, between 3,000 and 5,000 patients could "be in procedure".
"If we look at the figures of the Social Security, between January and December 2017, there are almost a million patients who left the Levothyrox Merck," says the lawyer, quoted by France Inter. "It still represents 31% of patients out of 3 million and because there is an underestimation of the gravity by the authorities, the measures that have been taken are not appropriate."
Coming soon, a new drug, TCAPS must make its appearance on the market. The trial of the class action against the Merck laboratory is scheduled for October 1st.
What does the formula change contain?
This change of formula consisted of replacing lactose, which coated the thyroid hormone, levothyroxine, into a tablet, with mannitol. It had been requested by the Medicines Agency (ANSM) to guarantee the stability of the product over time, which was not the case with the old formula. This change must be extended to the whole of Europe.
From the summer, the patients came forward: 5062 adverse effects were classified as serious and 14 deaths were identified by the ANSM, without a direct link with the new formula can be formally established. According to a pharmacovigilance survey, the adverse effects reported with the new formula are similar in type and severity to those of the old formula, but are more common (0.75% of patients). A case of suicide led to a thorough analysis of 79 cases of suicidal ideation disorders over the period. But the data from the cases are not comprehensive enough to allow a link between the adverse effects of psychiatric disorders with the new Levothyrox formula according to the ANSM.
Why Doctor took advantage of the congress of the French Society of Diabetology to interview Professor Serge Halimi, an endocrinologist fine connoisseur of thyroid diseases on Levothyrox. Find our show here.