Hyponatremia Induced Coma during Risperidone Treatment in 2 Cases of Schizophrenia / 대한정신약물학회지

ABSTRACT

Antipyschotics have been frequently reported being associated with hyponatremia. We have experienced two cases of severe hyponatremia with neurological symptoms in patients with acute schizophrenia who were treated with risperidone. Case 1 was a 33-year-old female who developed hyponatremia (Na+114 mEq/L) at 17 days after initiation of treatment with risperidone. Case 2 was a 41-year-old female who developed hyponatremia (Na+107 mEq/L) 5 months after treatment with risperidone. In both cases, polydipsia was not obvious. The exact cause of hyponatremia was uncertain, but we suggest that syndrome of inappropriate secretion of antidiuretic hormone due to risperidone may be the mechanism of hyponatremia in both cases. Although there have been many recent studies about the pathophysiology of hyponatremia among psychiatric patients, the exact mechanism remains unclear. There have been many case reports in the literature of hyponatremia associated with antipsychotics. We suggest that risperidone may be a potential drug that can cause hyponatremia and lead to life-threatening neurological symptoms in the early stage treatment, and that clinicians should monitor patients on a regular basis.