Acquired transient vasopressin deficiency by cannabinoids and other substances

Water movement across cell membranes through aquaporin water channels creates osmotic equilibrium between extracellular and intracellular fluid compartments. Plasma osmolality is tightly regulated by the kidneys and brain through the process of osmoregulation. The antidiuretic hormone, arginine vasopressin (AVP), is normally released from the posterior pituitary in response to increased osmolality or decreased intravascular volume. Defects in the synthesis or release of AVP result in AVP deficiency (AVP-D) and the syndrome of central diabetes insipidus, characterized by inappropriate aquaresis leading to hyperosmolality and insatiable thirst. While most cases of AVP-D are due to local mechanical, infiltrative, compressive, infectious, or inflammatory processes, some recreational and pharmacological substances can cause AVP-D. In this review, we discuss the history and current knowledge about these substances, including cannabinoids, ethanol, κ opioid receptor agonists, phenytoin, and anesthetic agents.