The UK Medicines and Healthcare products Regulatory Agency has issued new prescribing guidance for levothyroxine. This allows healthcare professionals to consider consistently prescribing a specific formulation known to be well tolerated by the patient.

This is very welcome news for patients who report persistent symptoms when switching between different levothyroxine formulations. 

It is usual for UK patients to be prescribed the generic drug and also for different formulations to be dispensed according to what the pharmacy can supply. For the majority of patients, this does not cause any issues. However, a small proportion of patients do experience variable thyroid function and associated symptoms when their levothyroxine formulation is changed. 

The MHRA has issued this guidance after considering data, including 335 Yellow Card reports patients have submitted reporting symptoms. The guidance allowing consistent prescribing for patients with persistent symptoms applies regardless of whether thyroid function is normal or not.

If symptoms persist and/or thyroid function varies despite taking consistently taking a specific product, healthcare professionals can also consider prescribing levothyroxine as an oral solution instead of tablets.

If you are experiencing persistent problems with levothyroxine, we would urge you to make your healthcare professionals aware of this guidance and also to report any adverse effects to the MHRA Yellow Card system

BTF medical advisor, Dr Salman Razvi said:

'Levothyroxine is one of the most commonly prescribed drugs in the UK. The vast majority of patients feel well on this medication. There are some, however, that appear to be sensitive to minor changes in dose or excipients (substances added to provide bulk, flavour or stability). The guidance from the MHRA should be welcome news for those for whom switching between products may have an unfavourable impact. As levothyroxine is prescribed generically (by its chemical name) the challenge now would be for clinicians (who prescribe), pharmacists (who dispense), and patients (who consume) to be fully aware of this guidance.'

MHRA levothyroxine prescribing guidance

May 2021