[Current options of treatment of hyponatremia]

During the past 50 years the molecular mechanisms of renal reabsorption of sodium and water have been described and molecules specifically interfering with these mechanisms have been developed (diuretics, vasopressin receptor antagonists). Chronic hyponatremia is caused by relative excess of free water, it occurs within a broad spectrum of diseases associated with hypervolemia (heart failure, liver cirrhosis), normovolemia and hypovolemia and it is a negative prognostic factor for patients with chronic heart failure and cirrhotic ascites. Vaptans (vasopressin antagonists, vasopressin V2-receptor inhibitors) reduce reabsorption of water in the distal nephron, they increase free water excretion and normalize serum concentrations of sodium in normovolemic and hypervolemic conditions associated with hyponatremia. Hyponatremia can be corrected (depending on cause, severity and speed of development) through the reduction of fluid intake, administration of a hypertonic solution NaCl, diuretics, oral administration of urea and by vaptans. The role of vaptans in the treatment of hyponatremia should be defined even better, in Europe vaptans can be used to treat the syndrome of inadequate antidiuretic hormone secretion (SIADH).Key words: hyponatremia - liver cirrhosis - heart failure - syndrome of inadequate secretion ADH - tolvaptan - vasopressin.