[Drug therapy of goiter. Iodine, thyroid hormones or combined therapy].

Abstract

Recent in vitro and in vivo data indicate that intrathyroidal iodine deficiency is the most important factor for the development of endemic goitre. Normalisation of the thyroid iodine content is essential to achieve regression of hyperplasia of iodine-depleted thyroid tissue. As clinical studies clearly demonstrate iodine should always be part of therapy of euthyroid diffuse endemic goitre. After therapy with levothyroxine alone the intrathyroidal iodine deficiency remains unchanged, and relapse of goitre will soon occur. There are the following indications for conservative therapy of euthyroid diffuse endemic goitre: 1. Children and adolescents should be treated by iodine alone (100-200 micrograms/die). 2. For adults a combined therapy with levothyroxine (100 micrograms/die) plus iodine (200 micrograms/die) is to be preferred to avoid the possible induction of thyrotoxicosis or autoimmune thyroid disease by high iodine doses (monotherapy with iodine would need 400-500 micrograms/die). In addition no reduction of goitre volume can be expected in adults older than 40 years because of an increasing number of thyroid nodular formations. 3. During pregnancy the combination therapy has advantages as high iodine dosages of iodine, potentially dangerous for the foetus, can be avoided whereas goitre formation in the mother is effectively suppressed and iodine deficiency in mother and child is compensated. Goitre therapy should be carried out at least for 6 months. The efficacy of goitre therapy should be controlled by sonographic determination of thyroid volume at least once a year after the end of treatment. An effective goitre prophylaxis with 100-200 micrograms iodine per day is recommended following the actual therapy period.