Tolvaptan, a Selective Oral Vasopressin V2-Receptor Antagonist, for Hyponatremia

The authors investigated whether tolvaptan, an orally active vasopressin V 2 -receptor antagonist that promotes electrolyte-free water loss, might improve hyponatremia. Serum sodium concentrations in patients with euvolemic or hypervolemic hyponatremia and mild or marked hyponatremia improved with therapy at day 4 and day 30. Tolvaptan holds promise for treating patients with hyponatremic states. Serum sodium concentrations in patients with euvolemic or hypervolemic hyponatremia and mild or marked hyponatremia improved with tolvaptan therapy. Tolvaptan holds promise for treating patients with hyponatremic states. Hyponatremia, the most common electrolyte derangement occurring in hospitalized patients, 1 , 2 is usually classified as hypovolemic, euvolemic, or hypervolemic. The secretion of arginine vasopressin appears to be of central importance in the decline of serum sodium concentrations in all these conditions. 1 , 2 Hyponatremia is reported to be associated with increased morbidity and mortality among patients with heart, liver, or neurologic disease. 3 – 8 Even mild chronic hyponatremia has been associated with subtle neurologic defects, manifested as impairments in balance and attention that can increase the incidence of falls. 9 These deficits may be reversed with the correction of the hyponatremia. Tolvaptan, a . . .