Description_x000D_ Packaging_x000D_ 5, 25 mg in glass bottle_x000D_ Biochem/physiol Actions_x000D_ Arginine vasopressin (AVP) plays an important part in circulatory and water homoeostasis and is important in renal hemodynamic alterations, water retention, and cardiac remodeling in congestive heart failure (CHF). Lixivaptan is an AVP V2-receptor selective antagonist that increases water excretion and normalizes serum sodium levels. Lixivaptan has been in clinical trials for hyponatremia associated with heart failure.