Hundreds of thousands of people in the UK are being prescribed thyroid drugs unnecessarily, according to international researchers. The study, published in the BMJ, advises against lifelong hormone treatment for mild underactive thyroid problems, known as hypothyroidism, stating there is insufficient evidence it helps.
The daily tablets do not appear to ease symptoms such as tiredness, low mood and weight gain, the researchers claim. However, experts stress that patients should not stop taking their medication without consulting their GP, and should discuss concerns at their next routine medication review.
Hypothyroidism affects about one in 20 people, but is more common in older age and among women. The thyroid gland in the neck produces hormones that help control energy levels and growth. Patients are often prescribed lifelong daily pills, such as levothyroxine (T4) or liothyronine (T3), to replace missing thyroid hormone. NHS figures show more than 32 million prescriptions for levothyroxine were issued in England in 2018.
The researchers analysed data from 21 trials involving over 2,000 patients, many over 65, and concluded that almost all adults with mild or 'subclinical' hypothyroidism will not benefit from hormone treatment. They argue that taking a pill and attending lifelong check-ups is burdensome, with 'uncertainty' over potential harms.
Current UK guidelines acknowledge that many patients will not need treatment, but suggest trying daily pills may be worthwhile for some. Dr Mark Vanderpump from the Society for Endocrinology said it can be reasonable to try the tablets for a few months and see how the patient feels. Prof Simon Pearce from Newcastle University noted that thyroid disease is being overtreated, but it is premature to recommend not treating young people based on available evidence.
Prof Helen Stokes-Lampard, chair of the Royal College of GPs, emphasised that thyroid hormones are powerful drugs and GPs only prescribe them if they believe there is genuine benefit, especially as it usually means long-term monitoring. She said the authors make a powerful case based on emerging evidence, and it is important that this new research is considered as clinical guidelines are updated.
