西妥昔单抗致低镁血症

Hypomagnesemia induced by cetuximab

1例62岁男性直肠癌术后吻合1：3复发伴肝转移患者自2012年7月19日起接受西妥昔单抗（第1周：716mg，第2～34周：447．5mg；1次／周静脉滴注）单药治疗。2013年3月28日为接受该药第35次治疗入院，实验室检查示血镁水平明显低下（0．35mmol／L），其他电解质水平、血生化指标、醛固酮、甲状腺功能和血、尿、大便常规检查均未见异常。复习患者病历资料，显示应用西妥昔单抗后其血镁水平逐渐降低，2013年1月31日降至0．51mmol／L。考虑系西妥昔单抗致低镁血症。给予硫酸镁10ml＋0．9％氯化钠注射液500ml静脉滴注，1次／d。应用硫酸镁第3天患者血镁升至0．54mmol／L，当日给予西妥昔单抗447．5mg，患者出院。继续在门诊接受补镁治疗，8d后复查，血镁0．82mmol／L。

A 62-year-old male patient received an IV infusion of cetuximab （cycle 1：716 mg, cycle 2-34 ： 447.5 mg） once weekly since July 19th, 2012 for postoperative anastomotie recurrence of rectal cancer and liver metastasis. Blood magnesium was 0.35 mmol/L and other electrolyte levels, biochemical indexes, aldosterone level, thyroid function tests, blood routine, urine routine and stool routine tests were normal when he was admitted to hospital on March 28, 2013. Review patients＇ medical records, blood magnesium level was gradually reduced and accompanied with the application of cetuximab, blood magnesium was 0. 51 mmol/L on January 31, 2013. It was considered that the cetuximab induced hypomagnesemia. An intravenous infusion of magnesium sulfate 10 ml plus 0.9% sodium chloride 500 ml once daily was given. On day 3, the blood magnesium was 0.54 mmol/L, and cetuximab 447.5 mg was given, he was discharged. Magnesium sulfate was given in outpatient clinic. Eight days later, his blood magnesium was 0.82 mmol/L.