End clap for cynomel (sodium liothyronine). In supply tension for several weeks, this drug indicated in the substitute treatment of hypothyroidies and certain goitles and nodules, will no longer be marketed from October 31 said Sanofi Winthrop Industrie at the ANSM.
In a press release, the agency announces that in replacement, and to ensure the continuity of patient treatment, the laboratory has undertaken to import its Thybon 20 Henning specialty into France (Liothyronine chlorhydrate), produced in Spain and marketed in Germany for more than 25 years.
“These imports will be effective at the time of stopping cynomel and will be followed by a request for AMM of Thybon in France to ensure lasting access to this medication, in order to avoid patients repeated treatment changes. There will therefore be no supply break between the end of Cynomel distribution and the start of provision of Thybon ”, assures the agency.
New prescription and thyroid hormone assays
This transition will not be without constraints for patients, who will have to provide a new prescription from their doctorand carry out thyroid hormone dosages (TSH, T4, T3), 6 to 8 weeks after the introduction or 6 to 8 weeks after any change of dose, as well as in the event of a significant variation in the weight or any symptom evoking a thyroid imbalance.
Constraints due to the difference in dosage between the two specialties -25 µg of sodium liothyronine equivalent to 24.18 µg of liothyronine base for cynomel and 20 µg of chlorhydrate liothyronine equivalent to 18.94 µg of liothyronine base for thybon -, and the galleic form -quadrisable tablet for cynomel and kissed Thybon- which can hinder a very fine adjustment of the dosage.
The ANSM has published a table summarizing the characteristics of the two treatments.
Beware of confusion with L-Thyroxin Henning
The agency also alerts the possible confusion between Thybon and the L-Thyroxin Henning, another specialty of Sanofi, due to the strong resemblance of the two external packages. “” We invite pharmacists to educate patients about this risk of confusion, in particular those taking these two treatments simultaneously She says.
To prevent errors, the ANSM asked the laboratory to affix a label in French on the Thybon sachets and to integrate into each sachet a letter and an information note intended for patients, informing them about the precautions of use. Sanofi will also send a note and a letter to healthcare professionals.