This butterfly-shaped, unpaired bone is located towards the front of the ... Arginine vasopressin (AVP) or antidiuretic hormone (ADH): This hormone serves several important functions, including ...

Tolvaptan is a vasopressin receptor antagonist. Vasopressin (a.k.a. ADH or antidiuretic hormone) helps to regulate water retention by absorbing water in the collecting ducts of the nephron.