Swinging From Hypothyroidism to Hyperthyroidism: A Rare Entity Yet With Different Pathophysiology (Case-Based Review)

Abstract

Although rare but some patients developed hyperthyroidism preceded by hypothyroidism after being treated with levothyroxine. I reported a 35-year-old male who developed hyperthyroidism after getting treated with levothyroxine for hypothyroidism. Patient showed evident clinical and biochemical hypothyroidism with TSH of 175 ?U/mL and free T4 of 2.7 pmol/L, and started on levothyroxine. Levothyroxine was stopped after 3 years as he had become euthyroid. However, over a period of 1 year, he gradually had developed thyrotoxic state with TSH less than 0.01 ?U/mL and T4 of 26 pmol/L and clinical symptoms of thyrotoxicosis. He has now started on methimazole 5 mg/day and will be followed up in 6 months. Therefore, physicians are required to have a frequent assessment of thyroid function test to identify the occurrence of this rare entity of swinging from hypothyroidism to hyperthyroidism in order to initiate proper treatment.




J Endocrinol Metab. 2016;6(4):127-128
doi: http://dx.doi.org/10.14740/jem370w