Selective V2 receptor agonist useful for the treatment of central diabetes insipidus is
a. Diabetes inspidus results due to decreased action of ADH. It may be central (due to less secretion of ADH from the posterior pituitary) or nephrogenic (ADH secreted is normal but it is not able to act in the kidney).
b. The treatment of central DI is to supply ADH from outside. ADH acts on V1 and V2 receptors. Action on V2 receptor (anti-diuresis) is useful for the treatment of diabetes insipidus whereas its action on V1 receptors (vasoconstriction) is responsible for adverse effects.
c. Desmopressin is a long acting selective V2 receptor agonist that can be used in the treatment of central DI.