TREATMENT OF EUTHYROID IODINE DEFICIENCY GOITER - EFFICACY OF THE COMBINATION OF L-THYOXINE AND 150-MU-G IODINE IN COMPARISON WITH MONO-L-THYROXINE

Background: In terms of the pathomechanism, TSH and intrathyroid iodin e deficiency are the interconnecting elements between alimentary iodin e deficiency and the growth and genesis of goiter. L-Thyroxine treatme nt for suppression of hypophyseal TSH production and supplementary iod ide have a synergistic effect in reducing the size of goiter. An indiv idual adaptation of the L-Thyroxine dose is necessary for optimal TSH suppression. Excessive suppression of the the TSH level prevents uptak e of iodine by the thyroid and thus compensation of the intrathyroid i odine deficiency. Combination therapy of an individually adjusted amou nt of L-Thyroxine with a small, mostly constant amount of iodine is a recognized concept of goiter therapy today. Administration of a combin ation preparation with an individually adjustable dose of L-Thyroxine and 150 mu g iodine complies with these recommendations and improves c ompliance since only one tablet is required. Patients and Methods: In the present study, the thyroid iodine supply, efficacy and tolerance o f such a combination preparation was tested for the first time in 49 p atients with euthyroid iodine deficiency goiter (group A). 45 patients receiving an individual L-Thyroxine therapy served as controls (group B). Results: Supplementation of individually dosable L-Thyroxine with 150 mu g iodide leads to a markedly raised iodine excretion in the ur ine (p < 0.005). This is an indirect indication of an improved thyroid iodine supply. Patients of group A showed a greater reduction of the thyroid volume (18.5% as compared to 16.8%, p = n. s.) and a more pers istent TSH suppression (lowering by 39% [group A] as compared to a ris e of 17% [group B]) in relation to the initial value (p < 0.004). This is attributable to the improved supply of iodine. Conclusion: The com bination therapy tested was tolerated just as well as the mono-l-Thyro xine treatment with better efficacy.