What is the principle of treatment for hypothyroidism?

For medical professionals only

• Drugs used to treat hypothyroidism are mainly thyroid hormones (see table below).
  
  
• Monotherapy with levothyroxine (L-T4) is preferred, and lifelong medication
  is required.
  
• The dose of _{L-T 4} therapy depends on the degree of hypothyroidism, etiology, age, special circumstances, body weight, and individual differences
  .
  
• The replacement dose of L-T₄ is 1.
  6-1.
  8 μg/kg/d for adults according to standard body weight, about 2.
  0 μg/kg/d for children, and 1.
  0 μg/kg/d for the elderly; Thyroid cancer is about 2.
  2 μg/kg/day after surgery, and the replacement dose needs to be increased by 20% to 30%
  during pregnancy.
  
• Ioderonine is a synthetic sodium triiodothyronate (T₃), which has fast action and short duration, and is suitable for rescue of myxedema coma
  .
  
• Dry thyroid tablets are dry preparations of porcine thyroid gland that have been rarely used
  due to their unstable thyroid hormone amounts and T3 supraphysiological doses.
  
• Serum thyroid-stimulating hormone (TSH) should be monitored 4 to 8 weeks after L-T₄ replacement therapy, and repeated every 6 to 12 months after treatment is met, or as often
  as clinically necessary.
  
• Primary hypothyroidism is adjusted to the L-T₄ dose according to TSH levels, and the treatment goal is individualized
  .
  
• Central hypothyroidism is dosed according to total thyroxine (TT 4) and free thyroxine (FT₄) levels, not TSH levels
  .
  
• Care should be taken during replacement therapy to avoid clinical or subclinical hyperthyroidism
  caused by overdose.