Do holding exercises or antimuscarinics increase maximum voided volume in monosymptomatic nocturnal enuresis? A randomized controlled trial in children.

PURPOSE We assessed prospectively the efficacy of holding exercises and/or antimuscarinics (oxybutynin chloride and placebo) for increasing maximum voided volume in prepubertal children with monosymptomatic nocturnal enuresis. MATERIALS AND METHODS We randomly allocated 149 children to 5 groups, namely holding exercises with placebo (group A), holding exercises with oxybutynin (group B), placebo alone (group C), oxybutynin alone (group D) and alarm treatment (controls, group E). Maximum voided volume was the greatest voided volume from a 48-hour bladder diary, and holding exercise volume was the greatest volume produced with postponement of voiding after a fluid load, once daily for 4 days. Study medication, holding exercise procedures and alarm treatment were administered for 12 weeks. RESULTS Holding exercises combined with placebo or oxybutynin significantly increased holding exercise volume and maximum voided volume, by 25% (p <0.001) and 21% (p <0.01), respectively, in group A, and by 43% (p <0.001) and 41% (p <0.001), respectively, in group B. Medication without holding exercises (groups C and D) did not increase holding exercise volume or maximum voided volume, and in these groups oxybutynin was not significantly superior to placebo. A borderline increase in holding exercise volume did not affect maximum voided volume in group E. Monosymptomatic nocturnal enuresis response was significantly lower with all 4 holding exercise volume modulating treatments (7%) compared to alarm therapy (73%). CONCLUSIONS In the treatment of children with monosymptomatic nocturnal enuresis maximum voided volume can be increased significantly through holding exercises, but not with oxybutynin chloride alone. Compared to controls, increasing maximum voided volume had a minimal effect on monosymptomatic nocturnal enuresis.