I am informed that there have been concerns raised in several Member States regarding the reformulation of a particular brand of medicine containing the synthetic T4 hormone levothyroxine sodium. The brand of levothyroxine in question does not have a marketing authorisation in Ireland.
Levothyroxine is a medicine used to treat a variety of different thyroid conditions. It is a medicine with a narrow therapeutic index, which means that small differences in dose or blood concentration may lead to changes in therapeutic outcomes or side effects.
In this case, the manufacturer of the particular brand of levothyroxine made changes to the inactive ingredients, also known as excipients, to increase the stability of the medicine and reduce potential variability in dosing. However, there have been reports of increased incidents of adverse drug reactions among patients who were changed to this new formulation in the Member States concerned.
None of the levothyroxine containing medicinal products granted a marketing authorisation in Ireland, and which are actively marketed here, have been subject to reformulation in recent years.
The Health Products Regulatory Authority (HPRA) is responsible for monitoring the safety, quality and effectiveness of medicines in Ireland, including reports of adverse drug reactions. This involves the operation of a national reporting system and inspection programme. Patients and healthcare professionals are encouraged to report suspected side effects, quality problems and other related issues through the HPRA website- http://www.hpra.ie//homepage/medicines/safety-information/reporting-suspected-side-effects
When new safety or quality information emerges the HPRA ensure that healthcare professionals are informed and when necessary new prescribing and dispensing advice is issued.
Patients taking levothyroxine-containing products should not stop taking their medicines. It is important that they continue to take their medicine as per their doctor’s instructions. If any patient has any questions or concerns about any medicine that they are taking they are encouraged to speak with their doctor of pharmacist.