Factors Affecting the Clinical Response to Desmopressin Treatment for Primary Monosymptomatic Nocturnal Enuresis in Children

INTRODUCTION: Desmopressin is the first-line treatment option for primary monosymptomatic nocturnal enuresis (MNE), particularly when nocturnal polyuria is a key symptom. This study aimed to investigate the factors affecting clinical response to desmopressin and relapse status in children with primary MNE during follow-up. METHODS: Files of 576 paediatric patients presenting with primary MNE between September 2022 and March 2025, who commenced desmopressin treatment, were analysed retrospectively. The patients' demographic and clinical data were recorded. The clinical response to treatment was categorised according to the classification system of the International Children's Continence Society. A Cox regression analysis was performed to identify the factors that predict both treatment success and relapse. RESULTS: The median age of the patients was 8 (IQR 7-10) years, and 322 patients (55.9%) were male. At the 3-month follow-up, a complete response was observed in 346 patients (60.1%), a partial response in 102 patients (17.7%), whereas 128 patients (22.2%) had no clinical response. Of the 448 patients who showed a clinical response, 148 (33%) experienced a relapse following the discontinuation of desmopressin at a median follow-up period of 8 months. The results of the multivariable analysis identified advanced age at admission (≥ 11 years old) (HR: 1.949, p < 0.001), no history of SARS-CoV-2 (HR: 1.921, p < 0.001), absence of constipation (HR: 1.851, p = 0.039) and no history of allergy (HR: 1.769, p = 0.042) as factors increasing the clinical response to treatment. The factors that may have caused relapse during follow-up were: a history of SARS-CoV-2 (HR: 3.918, p = 0.007); a history of allergy (HR: 3.845, p = 0.001); advanced age at admission (≥ 11 years old) (HR: 3.105, p < 0.001); and constipation (HR: 2.936, p = 0.001). CONCLUSION: According to our findings, desmopressin induced a clinical response in around three-quarters of cases, but relapse was observed in around one-third of patients. Advanced age at admission (≥ 11 years old), a history of SARS-CoV-2 infection, constipation, and allergies were found to be predictors of treatment response and relapse rates during follow-up. CLINICAL TRIAL REGISTRATION: As it was a retrospective study, registration was waived.