Objectives. To investigate the effects of oral oxybutynin chloride (OC) on standard urodynamic measures in children with myelomeningocele (MMC) and detrusor hyperreflexia.

Methods. Forty-one MMC children with detrusor hyperreflexia (19 boys and 22 girls, aged 2 months to 15 years; mean 4.9 years) were evaluated urodynamically before and within 3 months after initiation of oral OC therapy (0.2 to 0.3 mg/kg/day). Therapy with oral OC was always combined with clean intermittent catheterization (CIC).

Results. Oral OC treatment caused an increase in bladder capacity from 141 ± 96 to 197 ± 99 mL (+40%; P <0.01), a decrease in detrusor pressure at maximal capacity from 45 ± 32 to 28 ± 23 cm H₂O (−38%; P <0.01), and an increase in detrusor compliance from 6.5 ± 5.6 to 16.8 ± 13.7 mL/cm H₂O (+158%; P <0.01). Improvement in urodynamic measures and continence were correlated. After a follow-up of at least 2 years, effective protection of renal function was achieved in 38 of the 41 children (93%) with conservative therapy alone. Adverse effects resulted in discontinuation of oral OC treatment in only 2 cases.

Conclusions. Treatment with oral OC and CIC is effective and safe in children with MMC and detrusor hyperreflexia and should be initiated early when indicated by urodynamic findings.