一位 87 歲男性患者因發燒和寒顫入本院急診做進一步治療，當時診斷為 慢 性阻塞性肺疾病合併二次 感 染 ， 以 moxifloxacin, acetaminophen 和 ketorolac 治療。入院 8 小時後發燒緩解，但於離 院前，患者突然有心搏減緩、胸部緊縮和頭昏眼花的症狀發生，經檢查發現患 者 心 跳 40-45下 / 分，血 壓   126/64 mmHg，除蜂窩性組織炎外，其餘並無 異常。全血球計數除嗜中性白血球外皆 正常，其他包括心臟酵素和血漿生化值檢測皆於正常範圍。心電圖檢查顯示心搏徐緩、1 級房室阻斷、左心室肥大、Q波存於 V4-V6、QTc 間距明顯延長(560 毫秒)。隨後送住院經由遙測監護儀和心 電圖監控，於24小時後，患者心搏減緩、胸部緊縮和頭昏眼花症狀緩解。經與醫師討論本案例患者之藥歷、生化檢 驗值、心電圖及過去病史，我們推論患 者此次 QTc 間距延長原因，是病人在某 些危險因子如年紀大、心臟結構異常及 心搏減緩存在下，使用藥物 moxifloxacin 與 amiodarone 交互作用所致。
 

A 87-year- old man, suffered from fever and chills, came to the emergency room for further treatment. The chronic obstructive pulmonary disease with secondary infection was diagnosed. During  hospitalization, the  patient  was  treated with moxifloxacin, acetaminophen and ketorolac. After 8 hours, the fever subsided. Before discharged from the emergency room, the patient suddenly occurred  bradycardia, chest  tightness and dizziness. The vital sign examination found that he was afebrile with a pulse between 40 to 45 beats per minutes, and a blood pressure at 126/64 mmHg without other remarkable symptoms except cellulites. The laboratory examination of complete blood count,cardiac enzymes and serum chemistries except neutrophil were normal.The  electrocardiogram  showed sinus bradycardia, first degree AV block, left ventricular hypertrophy, Q wave in V4-V6,and prolonged QTc interval (560msec). The patient readmitted and was closely monitored on the telemetry and echocardiography. After 24 hours, the symptoms of bradycardia, chest tightness and dizziness got improved. After evaluated the medication history, laboratory examination, echocardiography, and past history, we concluded that his episode of QTc interval prolongation might be caused by the interaction between moxifloxacin and amiodarone under some existing risk factors including old age, structure heart disease and bradycardia.