Vasopressin antagonists include a range of compounds with varying selectivity, some of which have been in clinical use or in clinical trials since 2009 (Izumi Y et al. 2014; Imamura T et al. 2019).
The small molecule vasopressin receptor 2 (VR2) antagonists, known as vaptans , directly block the action of vasopressin at its receptors (V1A, V1B and V2). These receptors have a variety of functions, with the V1A and V2 receptors being peripherally expressed and involved in the modulation of blood pressure and renal function, respectively. The V1A and V1B receptors are expressed in the central nervous system. Thus, V1A has been associated with a variety of social behaviors in humans and animals.