Severe hyponatremia due to rosiglitazone use in an elderly woman with diabetes mellitus: a rare cause of syndrome of inappropriate antidiuretic hormone secretion

To describe the first case of syndrome of inappropriate antidiuretic hormone secretion with life-threatening hyponatremia due to rosiglitazone therapy. We describe the clinical, laboratory, and imaging findings of the study patient. An 89-year-old woman with a 5-year history of type 2 diabetes mellitus was admitted to the emergency department because of unconsciousness. She had reported generalized weakness for 15 days and nausea and vomiting for 3 days. Findings from laboratory analysis showed severe hyponatremia (sodium, 110 mEq/L). She had normal renal, cardiac, and adrenal function, and she did not have edema or volume depletion. The cause of hyponatremia was syndrome of inappropriate antidiuretic hormone secretion. We did not find any cause for her condition other than rosiglitazone, an antihyperglycemic drug that is increasingly being used in patients with type 2 diabetes mellitus. According to her medical history, rosiglitazone was prescribed 1 month previously after withdrawal of gliclazide. We stopped the rosiglitazone and administered hypertonic saline infusion to treat the hyponatremia. Saline infusion was stopped and blood sodium levels were stabilized in the normal range after 2 days. The patient's plasma sodium concentration has remained in the reference range at follow-up visits. This is the first reported case of syndrome of inappropriate antidiuretic hormone secretion as an adverse effect of rosiglitazone, and this drug should possibly be considered for addition to the list of drugs that cause this condition.