The use of vasopressin receptor antagonists in hyponatremia.

Hyponatremia is the most prevalent electrolyte disorder in hospitalized patients. Vasopressin plays an important role in the pathogenesis of this disorder through its action on the vasopressin type 2 receptor (V(2)R), leading to electrolyte-free water reabsorption. Multiple vasopressin receptor antagonists have recently been developed that differ in their specificity for V(2)R and V(1)R. These agents have applications in diseases that can result in hypervolemic and euvolemic hyponatremia, such as the syndrome of inappropriate antidiuretic hormone secretion, congestive heart failure and cirrhosis. V(2)R antagonists have demonstrated promise in the short-term correction of hyponatremia, although the long-term survival benefits of these drugs are less clear. This review discusses the physiology of vasopressin in hyponatremia, the clinical implications of the disorder and examples of individual therapeutics used in treatment strategies.