Plasma vasopressin and response to treatment in primary nocturnal enuresis.

AIMS: To examine the relation between nocturnal vasopressin release and response to treatment with the vasopressin analogue 1-desamino-8-D-arginine vasopressin (DDAVP) in children with primary monosymptomatic nocturnal enuresis. DESIGN: Children were recruited from a specific enuresis clinic and entered into a defined treatment programme. Nocturnal vasopressin concentrations were measured every 15 minutes over a four hour period during overnight admission. RESULTS: Sixty seven children were eligible for entry into the study, 35 of whom agreed to overnight sampling. There was a quadratic relation between mean plasma AVP and response to treatment with DDAVP, with very high or very low concentrations being unresponsive. Plasma AVP profiles ranged from low concentrations with little variability to high concentrations with wide variability. CONCLUSION: The ability to respond to DDAVP is related to endogenous AVP production and is influenced by neuronal patterning in early infancy. The best predictors of success with treatment were a past history of breast feeding, mean nocturnal AVP concentration, and the height of the child. The response was adversely affected by poor weight at birth and poor linear growth. The study suggests differing causes of nocturnal enuresis related to different patterns of AVP release.

The effectiveness of desmopressin in the treatment of childhood nocturnal enuresis: predicting response using pretreatment variables.

OBJECTIVE: To determine the factors that predict the effectiveness of desmopressin in the treatment of childhood nocturnal enuresis. PATIENTS AND METHOD: Sixty-six children with monosymptomatic nocturnal enuresis were treated with intranasal or oral desmopressin for a 4-week period. starting with a standard dose of 20 microg (0.2 mg oral) and increasing after 2 weeks where no progress was apparent to 40 microg (0.4 mg oral). Before treatment a range of variables (demographic, situational, enuretic history, physiological, parental attitude and child) were recorded. Three parameters of success acted as dependent variables, with stepwise linear regression models used to determine pretreatment predictors of success with desmopressin. RESULT: Each outcome variable produced a very similar model of predictors. Success, as assessed by the most dry nights over a 14-night period, was associated with less severe enuresis before treatment, a parental belief that the child's enuresis was unstable and higher birthweight. CONCLUSION: From the analysis, a model of arginine vasopressin release is proposed and the clinical implications of the findings addressed.