Lithium-induced thyrotoxicosis

An unusual case of lithium-induced thyrotoxicosis was also published. In this case a 46-year-old woman with bipolar disorder presented with confusion and agitation. She was toxic on lithixun with a level of 3.6 mM and received hemodialysis. She was also hyperthyroid with a free T3 of 7.5pg/mL (1.8-4.6), free T4 of 3.0ng/dL (0.7-1.8), and thyroglobulin of 218ng/mL (0.8-49) but TSH was <0.015 jiU/mL (normal 0.4—5.5), reflective of /n/pothyroidism. She received intravenous propylthiouracil and propranolol, and her condition improved markedly within one week with normalization of free T4 to 1.8ng/dL, but with still a low TSH of <0.015 nU/mL [95 ]. 

Lithium ions inhibit thyroxine release. Lithium salts can be used instead of iodine for rapid thyroid suppression in iodine-induced thyrotoxicosis. Regarding administration of lithium in manic-depressive illness, see p. 234. 

The antithyroid effect of lithium has occasionally been used to benefit patients. In a case of amiodarone-induced thyrotoxicosis that did not respond to antithyroid drugs and glucocorticoids, low-dose lithium normalized thyroid function (62). 

Boeving A, Cubas ER, Santos CM, Carvalho GA, Graf H. [Use of lithium carbonate for the treatment of amiodarone-induced thyrotoxicosis.] Arq Bras Endocrinol Metabol 2005 49(6) 991-5. 

Dickstein G, Shechner C, Adawi F, Kaplan J, Baron E, Ish-Shalom S. Lithium treatment in amiodarone-induced thyrotoxicosis. Am J Med 1997 102(5) 454-8. 

Bandyopadhyay D, Nielsen C. Lithium-induced hyperthyroidism, thyrotoxicosis and mania a case report. Q J Med 2012 105 83-5. 

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