Oral Levothyroxine for Myxedema Crisis: A Case Series from a Tertiary Referral Center

Myxedema coma is the most severe form of decompensated hypothyroidism and represents a rare but life-threatening endocrine emergency. Standard treatment involves IV levothyroxine; however, access to this formulation is limited in many low-resource settings. This study aimed to describe the clinical characteristics, management, and outcomes of patients with myxedema coma treated with high-dose oral levothyroxine in a tertiary referral center in Colombia.

We conducted an observational study of adult patients diagnosed with myxedema coma between January 2011 and December 2021 at Fundación Valle del Lili. Diagnosis was based on Popoveniuc criteria (>60 points) or presence of coma in the context of hypothyroidism. Data were collected from electronic medical records. All patients received oral levothyroxine, and clinical, laboratory, and outcome variables were analyzed.

Twelve patients were included (median age 66 years; 50% female). The most common precipitating factor was acute infection (41.6%). All patients received an oral loading dose of levothyroxine (median 500 µg), followed by high-dose maintenance therapy. Normalization of free T4 was observed in all patients by the fourth day. The intensive care unit admission rate was 100%, with a median stay of 11 days. Vasopressor support was required in 58.3%, and in-hospital mortality was 25%.

High-dose oral levothyroxine was effective in achieving early biochemical recovery in patients with myxedema coma. In settings where IV formulations are unavailable, oral therapy represents a viable and potentially life-saving alternative.