Fluctuation in Serum Sodium Levels Related to Ipragliflozin Administration in a Patient with Diabetic Nephropathy and Sequela of Traumatic Brain Injury.

A 46-year-old diabetic man underwent the removal of a hematoma caused by traumatic brain injury. After surgery, severe hyponatremia occurred. The subsequent administration of NaCl and fludrocortisone improved his laboratory findings. The patient was transferred to our hospital, and his insulin therapy was replaced by teneligliptin. One week later, ipragliflozin treatment was initiated and induced an immediate increase in the serum sodium levels. NaCl and fludrocortisone were therefore discontinued. However, hyponatremia recurred after ipragliflozin withdrawal due to a urinary tract infection. NaCl and fludrocortisone were initiated again, and the laboratory data improved. We herein report a case of serum sodium fluctuation related to ipragliflozin administration.