Impact of mirabegron on nocturnal enuresis in children with overactive bladder

Background: Nocturnal enuresis associated with overactive bladder (OAB) is a common pediatric voiding disorder that can disrupt daily life and psychosocial well-being. Mirabegron, a β3-adrenergic receptor agonist, has emerged as an alternative to antimuscarinic therapy for OAB. This study aimed to evaluate the therapeutic effect of mirabegron on nocturnal enuresis in children with OAB. Methods: This quasi-experimental study was conducted over 18 months in the Department of Pediatric Nephrology at the National Institute of Kidney Diseases and Urology, Dhaka. Thirty children aged 6–15 years with nocturnal enuresis and OAB were enrolled following informed consent. Clinical, demographic, urodynamic, and laboratory data were recorded. All participants received mirabegron 25 mg at bedtime for 3 months. Bedwetting frequency, urgency, and overall treatment response were assessed at baseline and at monthly follow-up visits. Results: The mean age of participants was 11.33±2.44 years, and 70% were male. Urodynamic evaluation showed that 60% had small-capacity, reduced-compliance OAB. The mean number of bedwetting episodes decreased significantly from 7.3±3.4 per month at baseline to 4.7±3.6, 0.33±0.66, and 0.1±0.3 at the 1st, 2nd, and 3rd follow-ups, respectively. Urgency also decreased progressively, with 90% of children achieving complete symptom resolution by the end of treatment. No adverse effects were reported. Conclusions: Mirabegron demonstrated marked effectiveness in reducing nocturnal enuresis among children with OAB, with significant improvement in both bedwetting frequency and urgency. Larger multicenter studies are recommended.