The Medicines and Healthcare products Regulatory Agency has told pharmacists to stop supplying an affected batch of Levothyroxine 12.5mcg tablets due to a lower than required assay result.

Levothyroxine, which is used to treat an underactive thyroid gland (hypothyroidism), contains levothyroxine sodium – of which over 2bn items of levothyroxine sodium were prescribed in December 2022.

MHRA told community pharmacists to stop supplying batch no. 214052 of the tablets, to quarantine all remaining stock within the batch and return it to suppliers using the suppliers’ approved process.

Manufacturer Teva UK recalled the batch after routine stability testing found a lower than required assay result.

MHRA said that patients should continue to take medicines from this batch as prescribed, but if they experience any adverse reactions or insufficient control of symptoms, they should seek medical attention.

It added that any suspected adverse reactions should also be reported via the MHRA Yellow Card scheme.

Yellow Cards are available in the BNF, MIMS Companion, and from the MHRA, or you can report on line at yellowcard.mhra.gov.uk. Pharmacists can also download and print a hard copy to send by post.

When completing the card, pharmacists should include their own details so the MHRA can get in touch for extra information if needed. They should also include some sort of patient identifier, for their own records, but not the patient’s name or other details that enable the MHRA to identify them. This maintains confidentially between the pharmacist and the patient.

Further information can be found on the MHRA website, or by contacting Teva UK.

Teva UK has been approached for comment.