A novel oral vasopressin V2 receptor antagonist for the treatment of acute decompensated heart failure and hyponatremia

Arginine vasopressin (AVID) is a nonapeptide hormone responsible for mediating serum sodium and serum osmolality by increasing water retention in the kidney. Tolvaptan is an oral selective vasopressin V 2 receptor antagonist that works to produce aquaresis (water diuresis without electrolyte excretion) by blocking the effects of AVP. This effect makes tolvaptan a viable treatment option for patients with acute decompensated heart failure (ADHF) and hyponatremia, Current studies of tolvaptan in patients with ADHF indicate that this agent is safe and effective in relieving the signs and symptoms of this condition without affecting mortality. Data from these trials also indicate that tolvaptan does not adversely affect renal function, blood pressure, or serum potassium in this patient population. This inert effect on mortality, renal function, and electrolytes sets tolvaptan apart from other therapies for heart failure, which are known to deleteriously affect these parameters. Tolvaptan has also been demonstrated to be effective in correcting hyponatremia in patients with heart failure, cirrhosis, or syndrome of inappropriate antidiuretic hormone. Tolvaptan is also being studied for the treatment of autosomal dominant polycystic kidney disease. In December 2007, FDA accepted an NDA for tolvaptan for the treatment of ADHF and hyponatremia. If approved, tolvaptan will be a new option for patients with these conditions.