[Long-term treatment with desmopressin in children with primary nocturnal enuresis. An international multicenter study].

Background: Desmopressin (an analogue of antidiuretic hormone) holds an important place in the treatment of primary nocturnal enuresis. According to some long-term trials its action is mainly symptomatic. The benefit of treatment and persistence of the effect in relation to the expected decline of enuresis in 15% children/1 year is discussed.

Methods And Results: The open multicentre trial lasted 42 months. In the first stage 265 patients (164 boys, 101 girls) aged 9.4 +/- 2.8 (5-18 years) were given desmopressin (nasal drops) to achieve a 4-week dry integral. Enuresis stopped in 207/265 (78.1%) children within six (median) weeks of treatment after an effective dose of 10.5 micrograms (median) based on titration. During the second stage 55/265 children (25 boys and 30 girls) proceeded with treatment for 2-30 (median 12) months, one boy did not complete the trial. An effective dose was administered for 3.5 months (median) and then the dose declined depending on the effect by 3.5 micrograms (1 drop) per months (median). In the titration stage enuresis receded in 89.1% (49/55) children. After the first year of the trial there were 72.7% responders (p < 0.001, as compared with the assumed decline), after two years 70.9% (p < 0.01) and after three years 61.1% children (p < 0.05). The trial was completed by 61.1% (33/54) children as respondents. 23 of them 17-38 months after termination of treatment. 29.6% (16/54) patients were relapsing responders on long-term treatment, 5.6% (3/54) patients completed the trial as partial responders and 3.7% (2/54) children as non-responders. Minor side-effects were recorded during the titration stage in 4.5% children, during long-term treatment 5.4% children. The osmolality of morning urine increased during treatment regardless of the final effect (p < 0.01). The authors did not find a significant relationship between age, sex, familial incidence of enuresis, period of treatment and the achieved effect.

Conclusions: The authors provided evidence of a rapid onset of the effect of desmopressin and a high effectiveness throughout the trial. The osmolality of the morning urine was not a reliable predictive factor of the effect. In the authors opinion long-term treatment is important for development of regulation and regression of complaints. During a relapse the authors recommend return to maintenance treatment and gradual discontinuation after 6-12 months. Desmopressin treatment is in the authors' opinion safe, well tolerated and very useful.