Australian endocrinologists are ‘mostly following’ international guidelines on the prescribing of hormone therapy for hypothyroidism, while use of liothyronine remains controversial, survey data show.

The poll of Endocrine Society of Australia members also suggests a link between each endocrinologists’ number of patients treated for hypothyroidism and their willingness to prescribe liothyronine (LT3), either alone or in combination with levothyroxine (LT4).

All of the 87 specialists who completed the poll agreed LT4 should be the first choice for the treatment of hypothyroid patients, with only 44% having prescribed LT3 in their clinical practice.

Half of those polled said they would consider combination hormone therapy in patients with normal thyroid stimulating hormone (TSH) levels who had ongoing symptoms of hypothyroidism.

But the inability of LT4 to restore normal physiology was ranked as the least likely explanation for persistent symptoms and less than a third said they would consider LT3+LT4 therapy for themselves if they had hypothyroidism.

All in all, the survey showed prescribing largely in line with international guidelines, the researchers noted in Clinical Endocrinology (link here).

Nevertheless, there was some discordance, which pointed to the need for more up-to-date guidelines, particularly around LT4 use in pregnancy, which was variable among respondents, they wrote.

Additionally, although 49% of respondents would consider LT3 + LT4 in patients with normal TSH who had ongoing symptoms of hypothyroidism, the inability of LT4 to restore normal physiology was ranked the least likely explanation for persistent symptoms and only 32% would consider it for themselves if they were diagnosed with hypothyroidism.

And in according with evidence, some 55% would not prescribe thyroid hormone to euthyroid individuals but 39% would consider use in euthyroid female infertility with high levels of thyroid antibodies and 11% in euthyroid patients with a simple goitre growing over time.

“Many questions regarding the treatment of patients with hypothyroidism with adequate biochemical control but ongoing symptoms remain including the benefits and risks of LT3 + LT4 combination therapy,” the authors wrote.

“Further research in this area, including that of nonmedication related factors, will help guide management of a very common condition and allow us to avoid low value treatments.”

Of note, 38% of respondents reported not having control over the brand of LT4 dispensed to their patients.