Effects of amiodarone therapy on thyroid iodine content as measured by x-ray fluorescence
Thyroid iodine content (TIC) was measured by x-ray fluorescence in 68 patients who had received amiodarone treatment for varying intervals (1 g/week for 1-120 months). Thirty-six patients were euthyroid; the mean TIC of the patients (n = 15), who had been treated for less than 12 months was 30 +/- 19 (+/- SD) mg, twice the normal mean value (14.6 +/- 5.0 mg), and it was 39 +/- 17 mg in those (n = 16) who had been treated for 12-60 months and 29 +/- 6 mg in those (n = 5) who had been treated longer (greater than 60 months). Nineteen patients were hyperthyroid and had elevated TIC values. Of them, 6 patients had a goiter; their TIC (50 +/- 19 mg) was not significantly different from that of the hyperthyroid patients with no goiter (55 +/- 29 mg), but they became hyperthyroid more rapidly. Thirteen patients were hypothyroid; none had TIC values above the normal range, and it was below 2.5 mg in 5 patients. A sequential study was undertaken in 11 euthyroid patients who had no detectable antithyroid antibodies. TIC did not increase during treatment in 2 patients; both developed hypothyroidism, which was transient in 1 despite continuation of amiodarone treatment. The TIC initially increased during amiodarone treatment in the other 9 patients, leveling off at the end of the first year. The TIC rose well above the upper limit of the normal range in 4 patients, of whom 2 became hyperthyroid during the second year of treatment. TIC remained within the normal range in the other 5 patients, of whom 3 became hypothyroid after 12-24 months of treatment (1 subclinical, 2 overt). Although the TIC was significantly higher in the patients with hyperthyroidism than in the patients who remained euthyroid, the TIC test cannot be used to predict the occurrence of hyperthyroidism.
- Research Organization:
- Institut Gustave-Roussy, Villejuif (France)
- OSTI ID:
- 5201347
- Journal Information:
- J. Clin. Endocrinol. Metab.; (United States), Journal Name: J. Clin. Endocrinol. Metab.; (United States) Vol. 66:4; ISSN JCEMA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
BIOLOGICAL ACCUMULATION
BODY
CHEMICAL ANALYSIS
CHEMOTHERAPY
DISEASES
ELEMENTS
ENDOCRINE DISEASES
ENDOCRINE GLANDS
GLANDS
GOITER
HALOGENS
HORMONES
HYPERTHYROIDISM
HYPOTHYROIDISM
IODINE
NONDESTRUCTIVE ANALYSIS
NONMETALS
ORGANS
PATIENTS
PEPTIDE HORMONES
THERAPY
THYROID
THYROID HORMONES
X-RAY EMISSION ANALYSIS
X-RAY FLUORESCENCE ANALYSIS