Hyponatraemia and the Syndrome of Inappropriate Antidiuretic Hormone Secretion Associated with Drug Therapy in Psychiatric Patients

Abstract

Hyponatraemia, the most common electrolyte disorder of all hospitalised patients, is particularly common in psychiatric patients. Hyponatraemia is generally defined as a serum sodium level of less than 135 mmol/L. Certain psychotropic medications may predispose to hyponatraemia, yet a causative role for most has not been firmly established and their effect is most likely to be idiosyncratic. Certain factors such as age, schizophrenia and a history of hyponatraemia or polydipsia should alert the clinician to the need for closer follow-up.