A Case of Methimazole-Resistant Severe Graves' Disease: Dramatic Response to Cholestyramine

ABSTRACT

A 22-year-old woman with severe Graves' disease was referred from a local clinic because of her refractory hyperthyroidism. She presented with exophthalmos, diffuse goiter, and tachycardia. She was treated with a maximal dose of methimazole and a beta-blocker for 2 months. However, her thyroid function test (TFT) did not improve. TFT showed a free T4 level of 74.7 ng/dL and a thyroid stimulating hormone (TSH) level of 0.007 µIU/mL. She was then administered cholestyramine (4 g thrice daily), hydrocortisone (300 mg/day) and methimazole (100 mg/day) which prepared the patient for surgery by reducing the free T4 level (4.7 ng/dL). The patient underwent a total thyroidectomy without experiencing thyrotoxic crisis. This case describes the use of cholestyramine for the first time in Korea in treating Graves' disease and provides limited evidence that cholestyramine can be an effective option.