Tolvaptan.: Treatment of heart failure, vasopressin V2 antagonist.

Congestive heart failure is a condition in which impaired cardiac function causes circulatory congestion. Although there is no cure, several classes of agents are available or under development to improve cardiac function, relieve symptoms and improve quality of life of patients. Arginine vasopressin (AVP) is a potent antidiuretic hormone that plays a crucial role in the regulation of free water absorption, body fluid osmolality, blood volume, cell contraction and blood pressure and its diverse actions are mediated by the G-protein-coupled receptor subtypes V-1, V-2 and V-3, The systemic vasoconstriction and dilutional hyponatremia seen in patients with congestive heart failure are due, in part, to abnormally high levels of circulating AVP. AVP antagonism is therefore a feasible strategy to prevent disease progression in heart failure. The orally active benzazepine tolvaptan is a V-2 receptor antagonist that has demonstrated excellent preclinical and clinical aquaretic effects indicating its potential efficacy in the treatment of hyponatremia seen in congestive heart failure as well as other conditions such as liver cirrhosis and renal pathologies.