The role of V2 vasopressin antagonists in hyponatremia

Hyponatremia is a frequent electrolyte disorder. It is often found in conge stive cardiac failure, liver cirrhosis, plasma volume contraction and in Si ADH. In these disorders hyponatremia is caused by nonosmotic vasopressin an d sustained fluid intake. This provides a rationale for V2 vasopressin rece ptor antagonists in the treatment of hyponatremia. There is now convincing evidence from different animal models of congestive cardiac failure that pe ptide and non-peptide V2 vasopressin antagonists effectively increase renal water diuresis and plasma sodium concentration. In addition, several of th e experimental studies also showed an improvement of hemodynamic changes of cardiac failure in response to V2 antagonists. Data in patients indicated that oral non-peptide V2-antagonists correct hyponatremia and may improve h emodynamic derangements in cardiac failure. In addition, experimental and c linical studies of V2 antagonists have been undertaken in liver cirrhosis a nd SiADH. In those studies hyponatremia was improved or corrected, too. Tak en together, V2 vasopressin antagonists promise to become therapeutic agent s in hyponatremic disorders. (C) 2001 Elsevier Science BY A-H rights reserv ed.