Desmopressin for bed wetting: length of treatment, vasopressin secretion, and response.

Fifty five children with nocturnal enuresis referred to a hospital enuresis clinic entered a controlled trial to compare the efficacy of one month and three month courses of intranasal desmopressin (Desmospray). There was no significant difference in outcome between the two groups. Overall 36% improved by at least two dry nights/week during treatment, but only five children (18%) in the one month group and three (11%) in the three month group became completely dry and only one in each group remained dry after treatment. To determine whether nocturnal polyuria was associated with a therapeutic response to desmopressin, the nocturnal urine volume, osmolality, and vasopressin concentration were measured in desmopressin responsive enuretics, desmopressin non-responders, and non-enuretic control children. There were no significant differences between the three groups. A three month course of desmopressin is no more effective than a one month course. Although many children will improve during treatment, only a small number become dry and most will relapse when treatment is stopped.