Tolvaptan is the first FDA-approved oral V(2) receptor antagonist for the treatment of euvolemic and hypervolemic hyponatremia, in patients with conditions associated with free water excess such as heart failure, cirrhosis, and the syndrome of inappropriate antidiuretic hormone secretion. Tolvaptan inhibits the binding of arginine vasopressin to the V(2) receptors on the collecting ducts of the kidneys resulting in aquaresis, the electrolytes sparing excretion of water. This article reviews the accumulated experience with tolvaptan and all the major clinical trials that were conducted to study its safety and efficacy and concludes by summarizing clinicians' views of its current application in clinical practice.
Keywords: arginine vasopressin antagonist; heart failure; hyponatremia; tolvaptan.