Desmopressin in the treatment of severe nocturnal enuresis in adolescents--a 7-year follow-up study.

OBJECTIVES

To evaluate the role of long-term oral desmopressin (over a 7-year follow-up) in refractory enuretics, particularly in assessing the potential curative effect, and to analyse the results for specific types of patient to obtain clues about possible mechanisms of cure.

PATIENTS AND METHODS

The effect of oral desmopressin was investigated in 25 adolescents (aged 11-21 years) with severe monosymptomatic nocturnal enuresis. The long-term study consisted of two 12-week treatment periods, with the efficacy of the drug assessed as the reduction in the number of wet nights per week. Subsequently, the patients were followed-up for up to 7 years. Close contact was maintained with the families over this period ('good doctoring' approach). At 3-, 5- and 7-year intervals after completing the study, patients were assessed for dryness, frequency, treatment and sleeping habits, using postal questionnaires and telephone follow-up.

RESULTS

At the end of the long-term study, 35% of the patients remained dry without therapy. Within 2 years of ending treatment, 15 patients were dry, compared with an expected estimate of six by spontaneous resolution, and after 7 years, 19 patients were cured. Nocturia occurred in 75% of the enuretic patients but in only 5% of the healthy controls.

CONCLUSIONS

Active treatment of primary nocturnal enuresis with oral desmopressin has a clinically significant effect on the cure rate, which is maintained after ceasing therapy. The cure rate was higher than would be expected from spontaneous recovery alone during the first 2 years of the study and there was a significant further increase in the cure rate 7 years after ending therapy, again greater than the expected spontaneous cure rate. There also seemed to be a better response to treatment when it was prolonged. Furthermore, this therapy is safe when administered in the long-term.