Use of liothyronine (T3) in hypothyroidism: Joint British Thyroid Association/Society for endocrinology consensus statement

Abstract

Persistent symptoms in patients treated for hypothyroidism are common. Despite more than 20 years of debate, the use of liothyronine for this indication remains controversial, as numerous randomised trials have failed to show a benefit of treatment regimens that combine liothyronine (T3) with levothyroxine over levothyroxine monotherapy. This consensus statement attempts to provide practical guidance to clinicians faced with patients who have persistent symptoms during thyroid hormone replacement therapy. It applies to non-pregnant adults and is focussed on care delivered within the UK National Health Service, although it may be relevant in other healthcare environments.The statement emphasises several key clinical practice points for patients dissatisfied with treatment for hypothyroidism. Firstly, it is important to establish a diagnosis of overt hypothyroidism; patients with persistent symptoms during thyroid hormone replacement but with no clear biochemical evidence of overt hypothyroidism should first have a trial without thyroid hormone replacement. In those with established overt hypothyroidism, levothyroxine doses should be optimised aiming for a TSH in the 0.3-2.0 mU/L range for 3 to 6 months before a therapeutic response can be assessed. In some patients, it may be acceptable to have serum TSH below reference range (e.g. 0.1-0.3 mU/L), but not fully suppressed in the long term.We suggest that for some patients with confirmed overt hypothyroidism and persistent symptoms who have had adequate treatment with levothyroxine and in whom other comorbidities have been excluded, a trial of liothyronine/levothyroxine combined therapy may be warranted. The decision to start treatment with liothyronine should be a shared decision between patient and clinician. However,

Use of thyroid hormones in hypothyroid and euthyroid patients: A survey of members of the Endocrine Society of Australia

“…2,11 LT4 therapy is effective for most patients and is safe however some patients remain dissatisfied with treatment. 7,8 Like in other countries surveyed, most respondents reported seeing in their practice less than 10% of LT4 treated hypothyroid patients with ongoing symptoms despite a normal TSH, with a higher percentage of such patients in our study seen by those who saw more hypothyroid patients per year. 10,[12][13][14][15][16][17][18][19][20][21][22] Respondents perceived the percentage to be similar or increased compared to 5 years prior, again like other surveyed countries.…”

“…23 Due to limitations of the clinical trials performed to date, in recent years international societies have included in their guidelines that LT3 + LT4 combination therapy can be considered in patients with normal TSH on LT4 who remain symptomatic without other cause identified for their symptoms, in discussion with the patient. 2,8,24 In our study, 44% of surveyed members of the ESA report prescribing LT3 containing medication (alone or in combination) in their clinical practice, with respondents treating more patients with hypothyroidism per year more likely to prescribe LT3. Although 44% of survey respondents are prescribing LT3 (alone or in combination), only 48% of those who are prescribing LT3 would consider it for themselves if they developed hypothyroidism and 44% of respondents who would not consider it for themselves would consider prescribing it to patients with normal TSH and ongoing symptoms of hypothyroidism, which is similar to the findings in Serbia.…”

“…4 However, more recent international guidelines suggest considering the use of combination therapy in patients who remain symptomatic on LT4 despite adequate biochemical control and where no other cause is identified for their symptoms. 2,6,8 Our study aims to understand how Australian endocrinologists manage patients with hypothyroidism, their use of LT3 + LT4 combination therapy and their use of thyroid hormones in euthyroid patients.…”

Designing a combined liothyronine (LT3), L- thyroxine (LT4) trial in symptomatic hypothyroid subjects on LT4 - the importance of patient selection, choice of LT3 and trial design

“…LT4 monotherapy satisfies the majority, but a significant minority remain dissatisfied because of persistent symptoms that impair QoL. A trial of LT3 is recommended in them by international specialist societies ( 30 , 47 , 68 ).…”

Liothyronine (LT3) prescribing in England: Are cost constraints inhibiting guideline implementation?

“…In clinical practice, physicians are primarily influenced by guidelines from expert societies such as the British Thyroid Association (BTA), who recommend the careful addition of LT3 using lower doses than the historical 20 mcg dose (whole or split) in the above subjects who have persistent symptoms with reduced QoL. The BTA have in their recent guidelines recommended the introduction of 5–10 mcg of LT3 (given twice daily) on a trial basis under expert supervision 8 . It is however important that any price differential does not act to disincentivize prescribing of the doses now recommended.…”