Myxedema Coma or Crisis Medication

Updated: Mar 27, 2017
  • Author: Mohsen S Eledrisi, MD, FACP, FACE; Chief Editor: George T Griffing, MD  more...
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Medication

Medication Summary

The goals of pharmacotherapy are to increase thyroid hormone levels, reduce morbidity, and prevent complications.

Thyroid hormones

IV dosage form has a long half-life, so it can be administered once-daily and is the preferred route of administration in patients with myxedema coma because gastrointestinal tract absorption may be compromised. It is preferred by many authorities given its slow onset of action and sustained effect, making adverse effects less likely to occur and serum levels easier to monitor. Lower doses are recommended for patients who have arrhythmias or coronary artery disease.

Liothyronine

Liothyronine (T3) has a short half-life and must be administered every 8 hours. Because of concerns about abrupt onset and fluctuating concentrations in tissues, coadministration of T3 with T4 is recommended. 

Oral levothyroxine is taken daily 30-60 minutes before breakfast.

Corticosteroids

Patients presenting with myxedema coma may have adrenal insufficiency and stress doses of IV steroids must be administered along with initial thyroid replacement until adrenal function has been determined to be normal. 

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Thyroid hormones

Class Summary

Immediate administration of intravenous levothyroxine is advised if myxedema coma is suspected.

Levothyroxine (Synthroid, Levoxyl)

In active form, influences growth and maturation of tissues. Involved in normal growth, metabolism, and development. IV dosage form has a long half-life (may be administered qd and is the preferred route of administration in patients with myxedema coma/crisis because GI tract absorption may be compromised). Preferred by many authorities, because the onset of action is slow and sustained, making adverse effects less likely to occur and serum levels easier to monitor. Administering only T4 assumes normal conversion to T3 by deiodinase activity, which is usually compromised in severe illness. IV dose of T4 is approximately one half to two thirds of the PO dose. Lower doses recommended if patient has uncontrolled atrial arrhythmia or recent MI.

Liothyronine (Cytomel, Triostat)

Synthetic form of the natural thyroid hormone, T3, converted from T4. T3 is the active form, but because peripheral conversion of T4 to T3 is compromised in patients who are hypothyroid, some authorities suggest combined IV T4 and T3 in these patients. However, patients with cardiovascular disease are at greater risk of arrhythmia and infarction.

T3 has a short half-life and must be administered q8h. Because of concerns about abrupt onset and fluctuating concentrations in tissues, experts advise coadministration of T3 with T4.

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Corticosteroids

Class Summary

Corticosteroids have anti-inflammatory properties and cause profound and varied metabolic effects. They modify the body's immune response to diverse stimuli.

Hydrocortisone (Solu-Cortef, Hydrocortone)

DOC because of mineralocorticoid activity and glucocorticoid effects. Patients presenting with myxedema coma/crisis may have adrenal insufficiency, and stress doses of IV steroids must be administered along with initial thyroid replacement until adrenal function has been determined to be normal.

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