FDA Adds Indication for Astellas’s Vaprisol

Astellas Pharma U.S., Inc. received approval from the FDA for Vaprisol, a receptor antagonist for the 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.

Hyponatremia is estimated to affect 4% of hospitalized patients in the U.S. each year. Severe cases are medical emergencies that can result in swelling of the brain, respiratory arrest and death. Hypervolemic hyponatremia results in edema (swelling of body tissues) and is often associated with congestive heart failure, severe liver disease and kidney failure.

In a randomized, double-blind, placebo-controlled study, intravenous administration of Vaprisol 40 mg/day for four days resulted in increased serum sodium levels in hospitalized patients with hypervolemic hyponatremia. Significant increases in serum sodium levels were observed within the first day of treatment with Vaprisol and continued throughout the treatment period. The most common adverse events associated with Vaprisol were infusion-site reactions.