Management of Persistent Hyponatremia Induced by Long-acting Injectable Risperidone Therapy

Abstract

We present the case of a 55-year-old Caucasian male with a history of schizophrenia presenting with severe hyponatremia attributed to long-acting injectable risperidone treatment. Antipsychotic-induced hyponatremia is an uncommon but serious side effect that should be considered when assessing individuals on chronic psychiatric regimens. In this report, we will discuss our treatment plan for the patient when water deprivation and hypertonic saline failed to correct his serum sodium levels. The goal of this case report is to raise awareness of severe hyponatremia as a side effect of long-acting risperidone, and to encourage further studies to create guidelines for its management when current protocols fail to correct sodium levels.

Hyponatremia and Psychiatric Diseases

“…Antipsychotic medications alone have been reported in the literature to be associated with hyponatremia; however, recently, the long-acting risperidone injectable treatment has been implicated in hyponatremia as well. In this case, the patient did not improve simply with the removal of risperidone, due to the extended half-life, and ultimately required Tolvaptan administration [17]. The half-life of these medications may be an important factor in determining the management of subsequent hyponatremia.…”