From the Guidelines
Myxedema, also known as hypothyroidism, is a condition that requires prompt medical attention, particularly in severe cases where it can lead to life-threatening consequences such as myxedema coma, characterized by bradycardia, hypothermia, and altered mental status 1.
Key Characteristics
- Myxedema can develop after a thyrotoxicosis phase of thyroiditis 1
- It is essential to evaluate TSH and FT4 levels for case detection in symptomatic patients, with low TSH and low FT4 indicating central hypothyroidism 1
Treatment Approach
- For asymptomatic patients with TSH levels between 4.5 and 10 mIU/L, continuing ICPi therapy with monitoring of TSH every 4-6 weeks is recommended 1
- In symptomatic patients or those with TSH levels persistently above 10 mIU/L, thyroid hormone supplementation should be prescribed, with monitoring of TSH every 6-8 weeks while titrating hormone replacement to achieve a TSH level within the reference range 1
- In severe cases (G3-4), ICPi therapy should be held, and hospital admission with inpatient endocrinology consultation may be necessary for IV levothyroxine dosing, steroids, and supportive care 1
Management Considerations
- Regular follow-up appointments with a healthcare provider are necessary to ensure proper thyroid hormone levels and adjust medication doses accordingly
- Treatment duration is often lifelong, and it is crucial to work closely with a healthcare provider to monitor treatment progress and adjust the treatment plan as needed
- In cases of uncertainty about primary or central hypothyroidism, hydrocortisone should be administered before initiating thyroid hormone therapy 1
From the FDA Drug Label
As replacement or supplemental therapy in patients with hypothyroidism of any etiology, except transient hypothyroidism during the recovery phase of subacute thyroiditis This category includes cretinism, myxedema and ordinary hypothyroidism in patients of any age Myxedema Recommended starting dosage is 5 mcg daily This may be increased by 5 to 10 mcg daily every 1 or 2 weeks.
Myxedema is another term for hypothyroidism, a condition where the thyroid gland does not produce enough thyroid hormones. 2 2
From the Research
Definition and Characteristics of Myxedema
- Myxedema, also known as hypothyroidism, is a condition characterized by severe deficiency of thyroid hormone, leading to multiorgan failure and potentially life-threatening complications 3, 4, 5, 6, 7.
- It can manifest as myxedema coma, a rare but lethal disorder that requires immediate medical attention 3, 4, 5, 6, 7.
Symptoms and Presentation
- Symptoms of myxedema coma include altered mental status, hypothermia, and slowing of other organ systems 4, 5, 6, 7.
- Patients may also exhibit physiologic alterations such as fatigue, weight gain, constipation, and cold intolerance 5.
- Myxedema coma can be precipitated by acute stressors like infection, myocardial infarction, cold exposure, and surgery in patients with poorly controlled hypothyroidism 4.
- Non-comatose presentations of myxedema can also occur, with symptoms like dyspnea, generalized edema, drowsiness, disorientation, and memory loss 7.
Diagnosis and Treatment
- Diagnosis of myxedema coma is based on clinical presentation, laboratory results, and thyroid function tests 3, 4, 5, 6, 7.
- Treatment involves thyroid hormone replacement, typically with intravenous levothyroxine (T4) and hydrocortisone until coexisting adrenal insufficiency is ruled out 4, 5, 7.
- Supportive therapy, including pulmonary and cardiovascular support, is crucial in managing myxedema coma 5, 6.
- Early recognition and treatment are essential to prevent fatal consequences 3, 4, 5, 6, 7.