[Therapy of euthyroid iron deficiency goiter. Effectiveness of a combination of L-thyroxine and 150 micrograms iodine in comparison with mono-L-thyroxine].

BACKGROUND: In terms of the pathomechanism, TSH and intrathyroid iodine deficiency are the interconnecting elements between alimentary iodine deficiency and the growth and genesis of goiter. L-Thyroxine treatment for suppression of hypophyseal TSH production and supplementary iodide have a synergistic effect in reducing the size of goiter. An individual adaptation of the L-Thyroxine dose is necessary for optimal TSH suppression. Excessive suppression of the TSH level prevents uptake of iodine by the thyroid and thus compensation of the intrathyroid iodine deficiency. Combination therapy of an individually adjusted amount of L-Thyroxine with a small, mostly constant amount of iodine is a recognized concept of goiter therapy today. Administration of a combination preparation with an individually adjustable dose of L-Thyroxine and 150 micrograms iodine complies with these recommendations and improves compliance since only one tablet is required. PATIENTS AND METHODS: In the present study, the thyroid iodine supply, efficacy and tolerance of such a combination preparation was tested for the first time in 49 patients 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 micrograms iodide leads to a markedly raised iodine excretion in the urine (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 persistent TSH suppression (lowering by 39% [group A] as compared to a rise of 17% [group B]) in relation to the initial value (p < 0.004). This is attributable to the improved supply of iodine.
CONCLUSION: The combination therapy tested was tolerated just as well as the mono-L-Thyroxine treatment with better efficacy.

RCT Entities:   Population Interventions Outcomes