Medication Summary

Initiate thyroid hormone replacement as the mainstay therapy for patients with myxedema coma. Patients may remain refractory to other treatment and supportive therapies until thyroid hormone replacement takes effect. Infusing thyroid hormone in the euthyroid patient is unlikely to result in significant morbidity except in patients with ischemic heart disease. Hormonal therapy should be instituted early in patients with a high clinical suspicion of myxedema coma prior to laboratory confirmation.

Monitor the patient's heart during hormone treatment, decreasing or discontinuing the dosage with any evidence of ischemia or dysrhythmia.

The magnitude of hypothyroidism dictates dose and route. Mild cases may be treated with gradual oral replacement, but patients with myxedema coma usually require large doses of IV replacement. General guidelines suggest administration of intravenous levothyroxine at a dose of 500-800 mcg. Alternatively, intravenous liothyronine can be given at a dose of 25 mcg.

Administer antibiotics if infection is suspected to be a precipitating event.

Physicians often recommend glucocorticoid replacement therapy because adrenal insufficiency may be concomitant (especially in patients with secondary hypothyroidism).

Class Summary

These agents are used for the replacement of thyroid hormone.

Liothyronine (Triostat, Cytomel)

View full drug information

Liothyronine is a synthetic form of natural thyroid hormone (T3) converted from thyroxine (T4); its short duration of activity allows quick dose adjustments in the event of overdosage.

Levothyroxine (Synthroid, Levothroid, Levoxyl, Thyquidity)

View full drug information

Levothyroxine is also known as T4; many physicians prefer the more gradual onset of action of this form of thyroid hormone.

Class Summary

These agents are used for prevention and/or treatment of adrenal insufficiency.

Hydrocortisone (Solu-Cortef)

View full drug information

Hydrocortisone is the drug of choice, owing to its mineralocorticoid activity and glucocorticoid effects.

Follow-up

Elshimy G, Correa R. Myxedema. StatPearls. 2020 Jan. [QxMD MEDLINE Link]. [Full Text].
Wiersinga WM, De Groot LJ, Beck-Peccoz P, Chrousos G, Dungan K, Grossman A, et al. Myxedema and Coma (Severe Hypothyroidism). 2000. [QxMD MEDLINE Link]. [Full Text].
Dubbs SB, Spangler R. Hypothyroidism: causes, killers, and life-saving treatments. Emerg Med Clin North Am. 2014 May. 32 (2):303-17. [QxMD MEDLINE Link].
Popoveniuc G, Chandra T, Sud A, Sharma M, Blackman MR, Burman KD, et al. A diagnostic scoring system for myxedema coma. Endocr Pract. 2014 Aug. 20 (8):808-17. [QxMD MEDLINE Link].
Lee CH, Wira CR. Severe angioedema in myxedema coma: a difficult airway in a rare endocrine emergency. Am J Emerg Med. 2009 Oct. 27(8):1021.e1-2. [QxMD MEDLINE Link].
[Guideline] Screening for congenital hypothyroidism: US Preventive Services Task Force reaffirmation recommendation. Ann Fam Med. 2008 Mar-Apr. 6(2):166. [QxMD MEDLINE Link].
Ono Y, Ono S, Yasunaga H, Matsui H, Fushimi K, Tanaka Y. Clinical characteristics and outcomes of myxedema coma: Analysis of a national inpatient database in Japan. J Epidemiol. 2017 Mar. 27 (3):117-22. [QxMD MEDLINE Link]. [Full Text].
Mourtzinis G, Adamsson Eryd S, Rosengren A, et al. Primary aldosteronism and thyroid disorders in atrial fibrillation: A Swedish nationwide case-control study. Eur J Prev Cardiol. 2018 Jan 1. 2047487318759853. [QxMD MEDLINE Link].
Teng W, Shan Z, Teng X, Guan H, et. al. Effect of iodine intake on thyroid diseases in China. N Eng J Med. Jun 2006. 354(26):2783-2793. [QxMD MEDLINE Link].
Hamnvik OP, Larsen PR, Marqusee E. Thyroid dysfunction from antineoplastic agents. J Natl Cancer Inst. 2011 Nov 2. 103(21):1572-87. [QxMD MEDLINE Link]. [Full Text].
Spiegel E, Shoham-Vardi I, Sergienko R, Landau D, Sheiner E. The association between birth weight at term and long-term endocrine morbidity of the offspring. J Matern Fetal Neonatal Med. 2018 Feb 21. 1-111. [QxMD MEDLINE Link].
Sanda S, Newfield RS. A child with pericardial effusion and cardiac tamponade due to previously unrecognized hypothyroidism. J Natl Med Assoc. Dec 2007. 99(12):1411-3. [QxMD MEDLINE Link].
Beynon J, Akhtar S, Kearney T. Predictors of outcome in myxoedema coma. Crit Care. 2008. 12(1):111. [QxMD MEDLINE Link]. [Full Text].
Sato Y, Yoshihisa A, Kimishima Y, et al. Subclinical Hypothyroidism Is Associated With Adverse Prognosis in Heart Failure Patients. Can J Cardiol. 2018 Jan. 34 (1):80-7. [QxMD MEDLINE Link].
Chrysant SG. The Current Debate over Treatment of Subclinical Hypothyroidism to Prevent Cardiovascular Complications. Int J Clin Pract. 2020 Mar 11. e13499. [QxMD MEDLINE Link].