Abstract
Vasopressin also known as Anti Diuretic hormone acting through V2 receptor is the primary physiologic determinant of the rate of free water excretion. In the last decade, knowledge of vasopressin receptors has increased significantly. Multiple vasopressin receptor antagonists have been developed with differences in their specificity to V2:V1 receptors. These agents have applications in conditions of hypervolemic and euvolemic hyponatremia like the syndrome of inappropriate antidiuretic hormone secretion, congestive heart failure, cirrhosis and perhaps in brain edema following traumatic brain injury. Although V2 receptor antagonist may have a proven role in certain condition, only few drugs are currently available and its use still remains limited.