Oral Levothyroxine is an Effective Option for Myxedema Coma: A Single-Centre Experience

Abstract

Introduction: Myxedema coma is an endocrine emergency with a very high mortality rate. As per the American Thyroid Association, initial thyroid hormone replacement for myxedema coma should be intravenous levothyroxine (LT4). However, in India, the availability of intravenous LT4 is limited. Often, crushed LT4 tablets are given through the enteral route when parenteral therapy is unavailable. No data or protocol is available for the administration of oral LT4 in myxedema coma. The aim of this study was to assess the effectiveness of oral LT4 in patients diagnosed with myxedema coma and to formulate a protocol for oral LT4 that can be used to guide the treatment of patients when intravenous LT4 is unavailable. Methods: This retrospective observational study included patients diagnosed with myxedema coma between January 2010 and December 2019. The diagnosis of myxedema coma was based on the diagnostic scoring system for myxedema coma proposed by Popoveniuc et al. [Endocr Pract. 2014 Aug;20(8):808–17]. Dosing of oral LT4 was decided as per our institutional protocol. Results: Fourteen patients (11 males and 3 females) with a median age of 67.5 years (range 11–82) with myxedema coma were included. All patients had central nervous system manifestations, and sepsis was the most common precipitating factor. The median myxedema score was 72.5 (normal ≤25), and the median length of hospital stay was 12 days (range 3–18). The oral LT4 regimen consisted of a loading dose of 300–500 μg, followed by taper over the next 3–5 days. With this regimen, 13 patients survived, and only 1 patient died. Conclusion: Oral LT4 is an effective treatment option for myxedema coma when intravenous LT4 is unavailable.