Purpose The standard treatment of hypothyroidism is levothyroxine (LT4), which is
available as tablets or soft-gel capsules in Denmark. This study aimed to investigate
Danish endocrinologists' use of thyroid hormones in hypothyroid and euthyroid patients.
Methods An e-mail with an invitation to participate in an online survey investigating
practices about substitution with thyroid hormones was sent to all members of the
Danish Endocrine Society (DES). Results Out of 488 eligible DES members, a total of
152 (31.2%) respondents were included in the analysis. The majority (94.1%) of responding
DES members use LT4 as the treatment of choice. Other treatment options for hypothyroidism
are also used, as 58.6% prescribe combination therapy with liothyronine (LT3) + LT4
in their clinical practice. LT4 + LT3 combination is preferred in patients with persistent
symptoms of hypothyroidism despite biochemical euthyroidism on LT4 treatment. Over
half of the respondents answered that thyroid hormone therapy is never indicated for
euthyroid patients, but 42.1% will consider it for euthyroid infertile women with
high antibody levels. In various conditions that could interfere with the absorption
of LT4, most responding Danish endocrinologists prefer tablets and do not expect a
significant difference when switching from one type of tablet formulation to another.
Conclusion The treatment of choice for hypothyroidism is LT4. Combination therapy
with LT4 + LT3 is considered for patients with persistent symptoms. Even in the presence
of conditions affecting bioavailability, responding Danish endocrinologists prefer
LT4 tablets rather than newer LT4 formulations, such as soft-gel capsules.
