左甲状腺素钠致低钾血症

Hypokalemia caused by levothyroxine sodium

1例85岁男性患者因缺血性脑卒中合并甲状腺功能减退接受左甲状腺素钠(LT4)50μg口服、1次/d替代治疗。次日实验室检查示血钾3.0 mmol/L,予氯化钾缓释片1 g口服、3次/d。6 d后,患者诉轻微活动后心跳加快,实验室检查示血钾3.3 mmol/L,予门冬氨酸钾镁片1片口服、3次/d。补钾治疗8 d后,患者血钾3.5 mmol/L,血压163/90 mmHg(1 mmHg=0.133 kPa)。予氯沙坦钾片50 mg口服、1次/d降压治疗。临床药师问诊得知患者在遵医嘱服用LT4的同时,继续服用自备的LT475μg、1次/d。嘱患者立即停服自备药,并将LT4剂量调整至75μg、1次/d。13 d后,患者血钾恢复至4.0 mmol/L,未再诉活动后不适。

An 85-year-old male patient received left thyroxine sodium(LT4)50μg orally once daily for replacement therapy because of ischemic stroke and hypothyroidism.Next day,laboratory test showed that blood potassium was 3.0 mmol/L.He was given potassium chloride sustained-release tablets 1 g orally thrice daily.Six days later,the patient complained of a rapid heartbeat after slight activity.Laboratory tests showed that blood potassium was 3.3 mmol/L and a potassium magnesium aspartate tablet was administered orally thrice daily.After 8 days of potassium supplementation treatments,the patient's blood potassiumlevelwas3.5mmol/L,whilethebloodpressureincreasedto163/90mmHg.Losartanpotassium50mg once daily was given orally.Clinical pharmacist consulted and learned that the patient continued to take his own LT475μg once daily while following the doctor's instructions to take LT450μg once daily.The patient was instructed to immediately stop taking his own medication and the LT4 dose was adjusted to 75μg once daily.Thirteen days later,the patient's serum potassium returned to 4.0 mmol/L and no further discomfort occurred.