Methimazole 是一個使用超過 50 年的抗甲狀腺藥物，它所引起的副作用大部份都很輕 微，但少見的顆粒性白血球缺乏症和極少見的再生不良性貧血，卻是危及生命，甚至是致 命的。
本文報告一位 31 歲女性使用 methimazole 引起的再生不良性貧血的案例，此病人因為 甲狀腺機能亢進，十年前曾接受手術，後來又復發，接受一個多月的 methimazole，propranolol 治療後，自行中斷了一個月，才又繼續接受 methimazole，propranolol 治療。服藥 10 天後， 出現發燒，喉嚨痛，咳嗽，食慾不振等症狀。做了骨髓檢查以及其它相關檢查，及排除其 他可能引起相同副作用的原因之後，診斷為 methimazole 引起的再生不良性貧血合併感染。 住 院 接 受 抗 生 素 和 抗 黴 菌 藥 物 ， 治 療 其 嗜 中 性 白 血 球 缺 乏 造 成 的 發 燒 ， 以 及 G-CSF (granulocyte colony stimulating factor)刺激顆粒性白血球的生成，並輸注紅血球和血小板改 善其血色素和血小板低下的情況。情況穩定後，出院繼續追蹤。
Methimazole, an antithyroid drug, has been used for more than fifty years, most of the side effects are minor, but some are serious and potentially lethal, such as agranulocytosis and aplastic anemia.
Here, we reported a case of aplastic anemia associated with methimazole therapy. A 31-year-old
woman with a history of hyperthyroidism, she received operation 10 years ago, but recurred recently. She had been treated with methimazole and propranolol for one month, but she stopped drug by herself for one month, and then, she received the drug again. Unfortunately, 10 days later, she presented with fever, sore throat, mild cough, and poor appetite befor administration. Bone marrow aspiration was performed, and methimazole induced aplastic anemia was suspected. Methimazole was stopped and appropriate intravenous antibiotics and antifungus therapy for neutropenic fever. Besides, granulocyte colony-stimulating factor (G-CSF) was administrated to stimulate the growth of granulocytes. PRBC and PLT transfusion were done for decreased HgB and PLT. Under such treatment, the patient’s general condition became stabilized with recovery of pancytopenia. Then the patient was discharged and received regular OPD follow up and treatment.
