[Development of hypothyroidism therapy with thyroid hormone].
The management of patients with primary hypothyroidism is straightforward. Recent studies suggest, however, that standard thyroid replacement therapy with thyroxine may not be completely effective in relieving the symptoms of hypothyroidism, and that there may be a role for combined use of thyroxine and triiodothyronine (T3) in the replacement therapy. Furthermore, animal studies suggest that the direct contribution by the thyroid to circulating T3 concentrations may be important, and that thyroxine alone may not be adequate treatment for hypothyroidism. In studies on thyroidectomized rats, it was found that the achievement of normal tissue concentrations of T3 required either the thyroxine at high doses which resulted in the suppression of TSH secretion, or the combined thyroxine/T3 treatment, which was able to normalize the serum thyroxine, T3 and the TSH concentrations, and the levels of thyroxine and T3 in most peripheral tissues. If the same is true of humans, there might be a more physiological replacement regimen for hypothyroid patients other than the replacement regiment of using thyroxine alone.
Fang
Ling
L
Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu 610041, China.
Tan
Tianzhi
T
D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy*; D013972:Thyrotropin / Q000008:administration & dosage* / Q000627:therapeutic use; D014284:Triiodothyronine / Q000008:administration & dosage* / Q000627:therapeutic use
D014284:Triiodothyronine; D013972:Thyrotropin