The May 2021 MHRA Drug Safety Update contains new prescribing advice for patients who experience symptoms on switching between levothyroxine products.

The advice for healthcare professionals states that:

• generic prescribing of levothyroxine remains appropriate for the majority of patients
• a small proportion of patients treated with levothyroxine report symptoms, often consistent with thyroid dysfunction, when their levothyroxine tablets are changed to a different product. In such cases prescribing a specific levothyroxine product known to be well tolerated by the patient should be considered
• if symptoms or poor control of thyroid function persist (despite consistent medication), prescribers should consider prescribing an oral solution formulation of levothyroxine

Dispensers are reminded to endorse prescriptions to include brand name or supplier.

If levothyroxine is prescribed generically, it is reimbursed according to the prices published in Part VIII of the applicable Drug Tariff. However, a prescription requesting levothyroxine by a specific brand name or supplier name is reimbursed according to the NHS list price published in the NHS dictionary of medicines and devices (dm+d). If no price is indicated against the product listing in the dm+d, payment for the non-Part VIII product is based on the dispenser’s endorsement (supplier name, price and pack size).