Desmopressin is used to control the amount of urine your kidneys make. Normally, the amount of urine you make is controlled by a certain substance in the body called vasopressin. In people who have "water diabetes" (diabetes insipidus) or certain kinds of head injury or brain surgery, the body does not make enough vasopressin. Desmopressin is a man-made form of vasopressin and is used to replace a low level of vasopressin. This medication helps to control increased thirst and too much urination due to these conditions, and helps prevent dehydration.
Desmopressin is also used to control nighttime bedwetting in children. It reduces how often your child urinates and decreases the number of bedwetting episodes.