Objective: The aim of the study was to compare the efficacy and safety of different doses of DDAVP spray treatment (20 to 40 mcg/day) in patients with primary monosymptomatic nocturnal enuresis (defined as three or more wet nights per week).
Material and methods: 237 patients (152 males, 75 females; age range 5-17 years), with no infections or organic abnormalities of the urinary apparatus and no neurological disorders, were admitted into the trial. The experimental design was planned as an "open study" with five different treatments schedules (5 groups). The daily doses of DDAVP at bedtime in groups 1 and 2 were 20 and 30 mcg, respectively, for 6 weeks. In groups 3 and 4 the daily doses for the first 2 weeks were 20 and 30 mcg, respectively, and then, after a washout period of 2 weeks, the daily doses for the two groups were 30 and 20 mcg, respectively. A dose-response study (20 to 40 mcg/day) was carried out in group 5.
Results: DDAVP spray therapy in primary monosymptomatic nocturnal enuresis was found to be resolutive in 70-75% of treated patients. No difference in response was found between the patients treated with the daily dose of 20 and those on 30 mcg. No important reactions were observed in patients treated with DDAVP spray at the different daily dose (20 to 40 mcg) or for different periods of time (up to 6 weeks).
Conclusions: DDAVP spray therapy at a dose of 20 mcg/day was effective in 70-75% of primary monosymptomatic nocturnal enuretics. In non-responders the daily dose of DDAVP should be increased to 30 to 40 mcg.