Thyroid hormone suppressive therapy of sporadic nontoxic goiter

Thyroid hormone has been used to reduce the size of sporadic nontoxic goiter since 1894. Noncontrolled clinical studies suggest that about two thirds of goiters respond to therapy, and a recent randomized clinical trial confirms the efficacy of suppressive therapy for sporadic nontoxic goiter. Efficacy is at least partly correlated with suppression of pituitary TSH production, response is usually evident by 3 months, relapse occurs when therapy is withdrawn, and nodular goiters may be less responsive than diffuse goiters. Some, but not all, series suggest that postoperative use of thyroid hormone suppressive therapy prevents recurrence of benign goiter. Three recent randomized trials suggest that thyroid hormone administered for 6 months to 3 years does not reduce the size of solitary thyroid nodules. About one third of nodules regressed in both treatment and placebo groups. Long-term studies are needed to define the effects of thyroid hormone suppressive therapy on the growth of goitrous lesions based on their underlying pathophysiology.