Levothyrox : effects of non-unusual but ” unpublished number “

Health 31 January, 2018


Published the 31.01.2018 at 08: 20am


Keywords :

Lévothyroxeffets secondairesenquête

Since the change, at the end of march, the formula of Levothyrox by Merck, thousands of patients have reported adverse effects, painful, or unbearable, on the 3 million who partake of it.
To memory, this format change only relates to the ” excipients “, the products are inert tablet, and aimed to respond to a request for the Drug Agency who wanted to ensure the stability of the drug.
The MSNA published the point of survey on the period from late march to September 15, 2017 were published on 10 October 2017.

A national survey

A national survey of pharmacovigilance was initiated by the MSNA during the provision of the new formula Levothyrox in march 2017, in order to analyze the reports of adverse effects reported. The first results of this survey covering the period from the end of march to the 15th September 2017 were published on 10 October 2017.
The continuation of the investigation carried out over the period from 15 September to 30 November 2017 on the basis of the cases recorded in the national pharmacovigilance (BNPV) confirms that the adverse effects reported with the Levothyrox new formula are similar in type and severity to those of the Levothyrox old formula.

A frequency unusual

Over the period from 15 September to 30 November 2017, 12 248 cases of adverse effects have been recorded in the national pharmacovigilance (BNPV). They have been analyzed, in addition to 5 062 case already analyzed in the period from the end of march to the 15th September 2017. These cases have been mostly reported by the patients (90 %).
Overall, across these two periods studied in the framework of the investigation of pharmacovigilance, the percentage of patients reporting adverse effects with the Levothyrox is estimated to be 0.75% of the treated patients (2.3 million patients).

The effects of the usual

Adverse effects the most frequently reported in the observations are : fatigue, headache, insomnia, dizziness, depression, muscle and joint pain, hair loss. These effects were already reported with the Levothyrox old formula with, however, a frequency unprecedented and unexpected.
Since the beginning of the investigation of pharmacovigilance, 19 deaths have been reported and analyzed, but it could not be established to link with the new formula of Levothyrox.
A case of suicide is reported has led to an in-depth analysis of 79 cases of disorders of a type of suicidal ideation over the period. The data from the case are not sufficiently complete to establish a link between adverse effects of psychiatric disorders with the new formula of Levothyrox according to the MSNA.

A binding time

Among all reported cases, 4030 cases contain information on the balance sheet of the thyroid, of which 1745 cases are documented vis-à-vis the chronology of decision-Levothyrox new formula and TSH values entered before or after the change of formula of Levothyrox.
These 1745 cases have been the subject of a detailed analysis. The latter confirms the possible occurrence (in about 1/3 of cases analyzed) imbalances and thyroid gland during the passage of Levothyrox old formula Levothyrox new formula.

Discordance with the side-effects and imbalance of the thyroid

The analysis also shows that 2/3 of the patients reported adverse effects were assays of TSH in the standards that are expected. The adverse event profile is similar in all patients whether they are hypothyroidism, hyperthyroidism, or with a TSH in the standards that are expected.
The analysis of the set of cases does not allow the identification of new adverse effects with Levothyrox new formula, nor of the explanatory factors.

Continued investigations

The data from this survey of pharmacovigilance will continue to be analyzed in the light of different investigative procedures. Indeed, in the framework of the monitoring of the specialities of levothyroxine, the MSNA launched in October 2017, a study of pharmaco-epidemiology on the basis of the data of the health Insurance. The results of the descriptive component are planned in the first quarter of 2018.
In addition, a survey of pharmacovigilance on adverse effects of other drugs on the basis of levothyroxine have been available since October of 2017 is also in progress. An analysis of the first results is expected in the 1st half of 2018 so as to have sufficient data.

In the end, the sick are suffering, but fortunately, the availability of several therapeutic alternatives has led to 2/3 of them to improve their quality of life.

The toll-free number information (0.800.97.16.53 ) is accessible from Monday to Friday from 9 hours to 19 hours to respond to patient questions.

To report any adverse reactions : www.signalement-sante.gouv.fr