Amiodarone goiter

A 67-year-old man took amiodarone 200 mg/day for 20 months, after which it was withdrawn 8 months later his serum TSH was suppressed and the free thyroxine and free triiodothyronine were both raised there were no thyroid antibodies and an ultrasound scan showed a diffuse goiter with a nodule in the right lobe and reduced iodine uptake (45). Histological examination of the nodule showed a papillary cancer. 

Thyroid function tests were measured before and after treatment of amiodarone-induced hyperthyroidism (n = 12) and the response to combined antithyroid and glucocorticoid treatment (n = 11) was recorded (61). One patient had type 1 hyperthyroidism, nine had type 2, and two probably had a mixed form. Six patients had diffuse hypoechoic goiters. The median time to euthyroidism (defined as a normal free T3 concentration) with a thionamide + prednisolone (starting dose 20-75 mg/day) was... 

De Wolf D, De Schepper J, Verhaaren H, Deneyer M, Smitz J, Sacre-Smits L. Congenital hypothyroid goiter and amiodarone. Acta Paediatr Scand 1988 77(4) 616-8. 

Amiodarone is mostly given in a daily dose of 200 mg. This dose contains about 7 mg iodine which amounts to 35-times the daily recommended dietary iodine supply. A healthy thyroid gland compensates this overdose of iodine (Wolff—Chaikoff effect). However, patients with (subclinical) thyroid autonomy (in a euthyroid goiter in an iodine-deficient region) or subclinical thyroid autoimmune disease are very susceptible to IIH because this autoregula-tory mechanism is disturbed. 

Note-. FT4 free thyroxine, T3 triiodothyronine, iL-6 interieukin-6. Amiodarone-induced hyperthyroidism (AiT) can be categorized into two subtypes, whioh are termed type 1 and type 2. Type 1 AiT is primariiy iodine-induced hyperthyroidism that deveiops in patients with underiying thyroid disease, suoh as nontoxio muitinoduiar goiter or Graves disease. Synthesis and reiease of thyroid hormones are increased in type 1 AiT. in contrast, type 2 AiT is a destructive thyroiditis that occurs in persons with no apparent thyroid disease Source-. Basaria and Cooper (2005). 

Goiter, hypothyroidism, and/or a rise in serum TSH concentrations have been reported following the ingestion of large amounts of iodine in medications, especially amiodarone (Martino et ai, 2001), ingestion of well water... 

Amiodarone-induced thyrotoxicosis occurred in a patient with an autonomously functioning nodular goiter [35 ]. 

Differentiating between the two types of thyrotoxicosis is difficult but important for implementation of the correct therapeutic strategy. Amiodarone should be avoided in patients with toxic nodular goiters and subtotal thyroidectomy may be the treatment of choice. 

Liang Y-L, Huang S-M, Peng S-L, Hsiao S-H, Hung H-C, Ou H-Y, Wu T-J. Amiodarone-induced thyrotoxicosis in a patient with autonomously functioning nodular goiter. Ann Pharmacother 2009 43(1) 134-8. 

However, these same characteristics make lithium a useful adjunct in the treatment of hyperthyroidism with i l. A 39-year-old woman with Graves disease who may have developed thyrotoxicosis secondary to treatment with amiodarone, an iodine-rich medication [92 ]. She was administered lithium 900mg/day for 12 days to increase uptake. When this was combined with two doses of 0.9 mg of recombinant human thyroid stimulating hormone (rhTSH), there was a fivefold increase in uptake [92 ]. In a retrospective study of 204 hyperthyroid patients (n = 163 Graves disease, n = 26 toxic multinodular goiter, and n=15 solitary toxic thyroid adenoma), 103 patients received alone (median dose 558 MBq) and 101 received 1 with lithium (median... 

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