Management of Primary Hypothyroidism: Statement by the British Thyroid Association Executive Committee

Statement by the British Thyroid Association Executive Committee

Onyebuchi Okosieme; Jackie Gilbert; Prakash Abraham; Kristien Boelaert; Colin Dayan; Mark Gurnell; Graham Leese; Christopher McCabe; Petros Perros; Vicki Smith; Graham Williams; Mark Vanderpump


Clin Endocrinol. 2016;84(6):799-808. 

In This Article


The ETA and ATA guidelines differ in scope although the key recommendations on the diagnosis and management of hypothyroidism are comparable. The ATA guidelines comprehensively address the management of hypothyroidism and include sections on inhospital management, secondary hypothyroidism, the use of thyroid hormone analogues, and ethical considerations for clinicians and researchers. The ETA document on the other hand focuses specifically on the use of combination therapy and includes carefully considered suggestions for prescribing L-T3 in practice.

Both guidelines strongly recommend that L-T4 remains the therapy of choice in hypothyroidism and do not support the routine use of L-T4/L-T3 combination therapy due to insufficient evidence from controlled trials, lack of long-term L-T3 safety data, and unavailability of L-T3 formulations that mirror natural physiology.

A key feature of both guidelines is the acknowledgement of the subset of L-T4-treated patients who suffer persistent symptoms despite adequate biochemical thyroid status. However, while both guidelines agree that a trial of L-T3 may occasionally be indicated in such patients, there are significant differences between the guidelines in the implementation of such a trial.

The ETA would consider a carefully monitored experimental trial of L-T3 if symptoms persist after comorbid conditions have been excluded. Such a trial should be conducted under specialist supervision, be reassessed after a period of 3 months and preferably include objective evaluations of response with standardized quality of life tools.

The ATA goes further by insisting that any such trial must be rigorously implemented, either as part of a clinical trial or N of 1 trial, with formal ethical and governance approvals. In addition, the ATA highlights the ethical and legal obligations inherent on clinicians managing hypothyroidism including the responsibility to avoid potentially harmful therapies without proven advantage over existing therapies. The authors further assert that the balance of clinical evidence on the benefits of combination therapy over L-T4 monotherapy would demand that further randomized controlled trials are indicated.

The 2011 RCP statement concluded that L-T3 'should be reserved for use by accredited endocrinologists in individual patients' but did not specifically address management strategies for L-T4-treated patients with persistent symptoms after nonthyroid causes are excluded. Thus, the current ETA and ATA guidelines can be seen as an addition rather than a departure from this position.