[Comparison of the effectiveness of two different dosages of levothyroxine-iodide combinations for the therapy of euthyroid diffuse goiter].
OBJECTIVE
Administration of levothyroxine and/or iodide can effectively reduce the volume of endemic goitre. However, TSH suppression during levothyroxine treatment may increase the number of recurrences through the persistence of intrathyroidal iodine deficiency. With special attention paid to the level of levothyroxine, a comparison was made of two dosages of combined levothyroxine and iodide.


METHODS
44 patients with diffuse euthyroid goitre were randomized to two treatment groups. Group A received 100 micrograms levothyroxine + 100 micrograms iodide, group B 75 micrograms levothyroxine + 150 micrograms iodide, all of them for three months. This was followed by three months without the medication. Intrathyroidal iodine concentration was measured at the onset of the study, then three months and six months later. At these same times thyroid volume was measured by ultrasound, as well as urinary iodine and various parameters of thyroid function.


RESULTS
Thyroid gland volume was reduced in both groups (group A: -17.3%; group B: -14.8%; p < 0.001). There was no significant difference of intrathyroidal iodine concentration and thyroid volume between both groups. After the treatment period, TSH suppression was more marked in group A, while TSH rise was greater in group B.


CONCLUSIONS
Both drug combinations resulted in comparable reduction of thyroid volume, while the intrathyroid concentration of iodine remained unchanged. The smaller rise of TSH after the treatment suggests that the dosage of 75 micrograms levothyroxine + 150 micrograms iodine is to be preferred.
Kreissl
M
M
Klinik und Poliklinik für Nuklearmedizin, Julius-Maximilians-Universität Würzburg.
Tiemann
M
M
Hänscheid
H
H
Rendl
J
J
Reiners
C
C
D000328:Adult; D004338:Drug Combinations; D004359:Drug Therapy, Combination; D005260:Female; D005858:Germany; D006043:Goiter, Endemic / Q000097:blood / Q000000981:diagnostic imaging / Q000188:drug therapy*; D006801:Humans; D007454:Iodides / Q000008:administration & dosage / Q000627:therapeutic use*; D007455:Iodine / Q000032:analysis / Q000172:deficiency*; D011446:Prospective Studies; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D013963:Thyroid Hormones / Q000097:blood; D013972:Thyrotropin / Q000097:blood / Q000187:drug effects; D013974:Thyroxine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D014463:Ultrasonography
D004338:Drug Combinations; D007454:Iodides; D013963:Thyroid Hormones; D013972:Thyrotropin; D007455:Iodine; D013974:Thyroxine