Thyroid hormone use in clinical practice by Israeli endocrinologists: a THESIS* questionnaire survey : *Treatment of hypothyroidism in Europe by specialists: an international survey.

Abstract

Objective: Several thyroid hormone formulations are available for treatment of hypothyroidism. This study aimed at evaluating the use of these treatment options by Israeli endocrinologists in various clinical scenarios.

Methods: Israeli Endocrine Society members were invited to participate in a web-based questionnaire, Treatment of Hypothyroidism in Europe by Specialists: An International Survey.

Results: 99.2% of respondents used LT4 tablets as first line therapy for hypothyroidism. Thyroid hormone replacement options considered by respondents included LT4 tablets (100%), soft-gel capsules (4.0%), liquid solution (15.4%), combined LT4 + LT3 (2.4%) and LT3 tablets (17.8%). In cases of impaired absorption or persistent symptoms, most would continue LT4 tablets (86.1% and 95.1%, respectively), of whom 39.0% noted that only tablets are available in Israel. In patients with normal serum TSH and persistent symptoms, 95.1% would continue LT4 tablets, 57.5% would consider the addition of LT3 whereas 24.4% stated that LT4/LT3 combination should never be used. In euthyroid patients, LT4 therapy was considered in infertile women with high levels of thyroid antibodies (33.6%) and for simple goiter growing over time (11.4%).

Conclusions: In Israel, LT4 tablets are the treatment of choice for hypothyroidism in most clinical scenarios, including in patients with impaired absorption or with persistent symptoms, for whom a combination therapy with LT4 + LT3 is considered by half of respondents. Other LT4 formulations are not widely available in Israel, thus are infrequently considered compared to other European countries. These data suggest that international guidelines regarding the use of various thyroid hormone formulations in specific clinical scenarios are warranted.