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Title: Treatment of Severe Hypothyroidism

Category: Endocrine

Keywords: Hypothyroidism, treatment (PubMed Search)

Posted: 7/20/2013 by Michael Bond, MD (Updated: 3/3/2026)

Treatment of Severe Hypothyroidism

We do not see patient's with severe hypothyroidism often, but it is important that they be treated aggressively. Some treatment pearls are

  • Rule out aggravating cause (i.e.: infection [UTI, pneumonia], myocardial infarction)
  • Start IV levothyroxine dosing
    • Initial dose 400-500 mcg. This is a large dose but it only saturates the thyroid receptors and will not cause a rebound hyperthyroidism state.
    • Daily dose 100 mcg/day
  • Consider starting Dexamethasone/hydrocortisone
    • Patients may also have adrenal insufficiency from primary pituitary failure or may have secondary adrenal suppression due to the severe hypothyroidism.  If dexamethasone/hydrocortisone is not provided they may develop severe adrenal insufficiency once you kick start their metabolism.