Methimazole 為一抗甲狀腺藥物。常見不良反應有關節炎、顆粒性白血球低下、腸胃不適、皮膚紅疹、黃疸及掉髮。此案例為一位女性因使用methimazole 治療葛瑞夫茲氏症 (Graves’ disease) 引起疑似胰島素自體免疫症候群造成之低血糖症狀。此種案例雖少見，但臨床醫療人員仍須隨時注意、密切監測病人是否有發生藥物不良反應。

Methimazole is an anti-thyroid agent. Its adverse effect includes arthralgia, agranulocytosis, gastrointestinal upset, skin rash, jaundice and alopecia. We have a case report about a woman who use methimazole to treat Graves’ disease and develop hypoglycemic symptoms due to suspect insulin autoimmune syndrome. Although this adverse effect is uncommon, clinicians should be familiar with the possibility and monitor adverse effect when there is a doubt.