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.