Arginine vasopressin antagonists for the treatment of heart failure and hyponatremia.

Arginine vasopressin has attracted attention as a potentially important neurohormonal mediator of the heart failure (HF) syndrome and hyponatremic states in humans1 because vasopressin influences renal handling of free water, vasoconstriction, and myocyte biology.2,3 Several vasopressin antagonists are under development,4 and one of these agents, conivaptan, recently received US Food and Drug Administration approval for short-term intravenous treatment in patients with euvolemic or hypervolemic hyponatremia.