VASOPRESSIN SUPPRESSION Arginine vasopressin (AVP), also known as vasopressin, antidiuretic hormone (ADH) or argipressin, is a mammalian hormone that is released from the body. It has been used as a treatment for PKD. The drug Samsca (tolvaptan) is such a drug. Researchers tried to see if the same effect could be achieved through drinking 4 liters water daily. This did suppress vasopressin.