VOIDING dysfunction, particularly overactive bladder (OAB), is a common concern in the pediatric population, affecting 17-22% of children over five years of age. This condition is marked by symptoms such as urinary frequency, urgency, and nocturia, often without underlying infections or other pathologies. Diagnosis typically involves a combination of history-taking, voiding diaries, and specific questionnaires like the Dysfunctional Voiding Scoring System (DVSS), with attention given to any associated bowel dysfunction, particularly constipation, which increases the likelihood of voiding issues.
Treatment for paediatric OAB begins with behavioural urotherapy, focusing on education, fluid management, and appropriate voiding techniques. However, for more severe cases, behavioural therapy often shows limited efficacy. This is where pharmacological intervention comes into play, with antimuscarinics like solifenacin being a standard treatment. Yet, these medications often lead to side effects such as dry mouth, headaches, and constipation, exacerbating symptoms.
More recently, mirabegron, a selective beta-3 adrenergic agonist, has emerged as a promising alternative. Mirabegron works by relaxing the bladder wall, providing an option for children who do not respond to behavioural therapy or traditional antimuscarinics. While its effectiveness in adults has been well-documented, its use in children has only recently been explored, with a few studies offering promising results. The FDA approved mirabegron for use in children in 2021, marking a significant development in paediatric urology.
A recent study comparing the efficacy of mirabegron and solifenacin in children with OAB revealed that both treatments were equally effective in reducing symptoms like daytime frequency and nocturnal enuresis. Notably, mirabegron was associated with fewer side effects, including a reduced risk of constipation, making it a potentially better choice for first-line treatment. In the study, 67% of patients on mirabegron showed a significant reduction in wet nights, comparable to the 69% of patients on solifenacin. Moreover, mirabegron had a high adherence rate of 85.7%, with fewer patients discontinuing treatment due to side effects.
Though the study’s small sample size and short duration present limitations, the results suggest that mirabegron may offer an effective and safer alternative to solifenacin in treating paediatric OAB. Future studies with longer follow-ups are essential to further assess the long-term safety and efficacy of mirabegron in this population.
Katie Wright, EMJ
Reference
Mansour I et al. Efficacy and safety of mirabegron compared to solifenacin in treatment of non-neurogenic overactive bladder in children: a randomized controlled trial. Int Braz J Urol. 2025;51(2):e20240425.
