Safety and short-term efficacy of mirabegron in children with valve bladder: a pilot study

This pilot study aims to assess the short-term efficacy and safety of mirabegron in valve bladder, an important cause of persistent hydronephrosis after successful treatment of posterior urethral valves (PUV).

Twenty-two patients with early valve bladder (no residual PUV; persistent hydronephrosis, wetting and urodynamic evidence of detrusor overactivity) were included. Three subjective parameters: frequency, wetting episodes; patient perception of bladder condition score (PPBC) and four objective parameters: uroflow index (UI = Qave/Qmax), voided volume (VV = voided volume/ expected bladder capacity), maximum filling pressure (P det-max) and society of fetal urology (SFU) hydronephrosis grading were analysed pre- and post-3-month treatment with mirabegron (0.5-1 mg/kg/day). All patients were observed for heart rate, BP, ECG changes during therapy.

There was significant reduction (p = 0.001) in mean frequency (pre 15; post 10), wetting episodes (pre 5; post 2) and PPBC (pre 4; post 3). There was significant improvement (p = 0.01) in mean UI (pre 0.3; post 0.5), VV (pre 0.54; post 0.72), Pdet-max (pre 42; post 25) and hydronephrosis grade (pre 3.5; post 2.2). There were no significant side effects.

This pilot study establishes short-term efficacy and safety of mirabegron in valve bladder with overactivity. Further larger long-term studies are warranted.