Vasopressin antagonists in the treatment of water-retaining disorders

The tools available to physicians for the treatment of hyponatremia, the most common of electrolyte disorders, are limited by lack of effectiveness, compliance difficulties, and toxicity problems. For this reason the development of novel oral antagonists of vasopressin provide a new approach to the management of these disorders. Since vasopressin plays a central role in the pathogenesis of most hyponatremic disorders, the inhibition of binding of the hormone to its receptors is likely to provide a most reliable and reproducible response leading to increases in free water excretion. This article reviews many of the studies that have been undertaken with this new class of agents, both in hypovolemic and hypervolemic settings.