FDA clears Astellas' Vaprisol for hypervolemic hyponatremia

The US subsidiary of Japan's Astellas Pharma has received Food and Drug Administration approval for its Vaprisol (conivaptan HCl injection), an arginine vasopressin receptor antagonist, for the intravenous treatment of hypervolemic hyponatremia in hospitalized patients. Vaprisol, discovered and developed by Astellas, is the first drug specifically indicated for the treatment of both euvolemic and hypervolemic hyponatremia, potentially life-threatening conditions that occur when the body's blood sodium level falls significantly below normal. Vaprisol was approved by the FDA as a treatment for euvolemic hyponatremia in December 2005, and has been marketed by Astellas since April 2006.

Hyponatremia is estimated to affect up to 4% of hospitalized patients in the USA each year. While many with hyponatremia have no symptoms, severe cases are medical emergencies that can result in swelling of the brain, respiratory arrest and death. Hypervolemic hyponatremia, which occurs when the total body water increase is greater than the body's serum sodium levels, resulting in edema (swelling of body tissues) and is often associated with congestive heart failure, severe liver disease and kidney failure.