Long-term desmopressin response in primary nocturnal enuresis: open-label, multinational study.

Background: Primary nocturnal enuresis (PNE) is a distressing condition, particularly in severe cases (> or = 3 wet nights/week). A prevalent pathophysiological mechanism, especially in monosymptomatic PNE (PMNE), is commonly believed to be an insufficient increase in night-time release of antidiuretic hormone. Desmopressin, a synthetic analogue of antidiuretic hormone, has been shown to reduce the number of wet nights experienced by PMNE patients in several controlled trials.

Aim: This study was performed to evaluate desmopressin treatment in the real-life clinical setting and was a large-scale, 6-month investigation of efficacy and safety in patients with severe PNE. Predictive factors for desmopressin response were also evaluated. A total of 744 children aged 5 years and above from four countries were involved in the study.

Results: At baseline, patients had a median of 6 wet nights/week; at 6 months, 41% of patients had experienced > or = 50% reduction in the mean number of wet nights. Long-term desmopressin treatment was consistently well-tolerated across all ages, with 5% of patients experiencing any treatment-related adverse events. The strength of treatment response was associated with nocturnal diuresis (p < 0.0001) and age (p = 0.0167) in logistic regression analyses. Compliance and dosage were also associated with response and more patients experienced > or = 50% reduction in wet nights after 6 months' treatment than earlier in the study, suggesting the value of persistent treatment.

Conclusion: This study shows that long-term desmopressin treatment in the clinical setting is effective and well-tolerated in PNE patients of 5 years and upwards. Early improvements in bedwetting of any appreciable magnitude may be rewarding, may facilitate compliance and enable good long-term response.