INTRODUCTION AND OBJECTIVES: The recent discussion on the safety-issue of desmopressin as a spray in children with MNE, has led to the withdrawal of the spray for the indication of enuresis. Lane Robson concluded in his recent review, that the tablet is much safer, prospective acquired data on this topic are limited. The aim of the study is to evaluate the long-term safety profile of oral desmopressin in children with PNE.

METHODS: Prospective open-label, multinational, phase IV, observational study with up to 6 months follow up. Patients enrolled from 86 centres in four countries (UK, Canada, Germany, and France). Adverse events (AEs) were defined as any symptom occuring during the observation period. Study-population: 936 screened, 744 enrolled, aged 8.7y ± 2.5, 531 males, dose 0.2 – 0.6 mg desmopressin as an oral tablet. Duration of treatment 148 ± 77 days.

RESULTS: 404 AEs in 222/744 (30%) patients were registered: 89 gastrointestinal (15 upper abdominal pain, 14 diarrhoea, 13 gastroenteritis, 24 vomiting), 18 general symptoms, including 14 pyrexia, 91 episodes of infection, 36 nervous system (35 headache), 12 psychiatric AEs, 85 respiratory AEs and 20 skin AEs. The incidence of AEs was constant in the 4 participating countries. 2% withdrawals for potential drug related side-effects. No deaths, and 8 serious AEs (including appendicitis), but none of them was drug related. Hyponatraemia was not documented. The safety profile of desmopressin is similar irrespective of age or gender.

CONCLUSIONS: The Drip study is the largest (n=744) prospective long-term follow up study. Long-term desmopressin treatment is well tolerated in children with PNE with a good safety. Only in 5% of 404, causality to the drug could not fully be excluded. No serious AEs were related to the drug. Incidence of AEs during study period are comparable to the symptoms mentionned during the clinical history at intake visit, making causality of the drug unlikely. Recently the spray was withdrawn by the FDA, putting a lot of pressure on the prescription of desmopressin in MNE. These data are reassuring for the use of desmopressin as oral tablets.

Source of Funding: Supported by a Ferring Pharmaceuticals, Ltd. research grant.