Effects of thyroxine as compared with thyroxine plus triiodothyronine in patients with hypothyroidism.

A randomized, double-blind, crossover study found inclusion of T3 in thyroid hormone replacement improved cognitive performance, mood, physical status, and neuropsychological function in hypothyroid patients. Two-thirds of patients preferred T4 plus T3, and tended to be less depressed than after treatment with T4 alone. Patients and their physicians may wish to consider the use of sustained-release T3 in the treatment of hypothyroidism, particularly when the response to levothyroxine (T4) has not been complete.

J Endocrinol Invest 2002 Feb;25(2):106-9