約70% Phenytoin 引起肝毒性的病人會有合併過敏反應特質，這是一種無法預期的特異性(idiosyncratic)反應，病人會伴隨血清中的轉胺酶上升，死亡率高達10-50%。本案例是一位83 歲男性病人，過去病史有冠心病 (coronary artery disease, CAD)、末期腎臟疾病(end-stage renal disease, ESRD)、高血壓 (hypertension)、胃潰瘍 (gastric ulcer)、周邊動脈阻塞疾病 (peripheral arterial occlusive disease, PAOD) 等。於住院期間使用augmentin、colchicine、flucinazole、meropenem、moxifloxacin、phenytoin 及ranitidine 等7 種與肝毒性有關的藥物，根據檢驗值與用藥時間來推衍，phenytoin 與不良反應之間關聯性依據Naranjo評估為5 分屬於很可能，因此，phenytoin 是主要引起此病人肝毒性之藥品，藉此案例報告來進一步探討。
 

More than 70% of the patients with heptotoxicicty induced by phenytoin, also combined with hypersensitivity reaction. The unpredictable reactions are mostly idiosyncratic, and the mortality rate is up to 10-50%. This case of a 83-year-old male patient had the past history of coronary artery disease (CAD), end-stage renal disease (ESRD), hypertension, gastric ulcer, peripheral arterial occlusive disease (PAOD), etc. During hospitalization, 7 kinds of hepatotoxicity related drugs were used, including augmentin, colchicines, flucinazole, meropenem, moxifloxacin, phenytoin, and ranitidine. The correlation between phenytoin and adverse drug reaction was evaluated with the Naranjo,s scale according to laboratory data and time for medication. The score was 5 and represented “probable”.Therefore, the hepatotoxicity induced by phenytoin was suspected. This cases report will further discuss with phenytoin about adverse drug reaction.