Comparison of the Effects by Obybutynin and Tolterodine on Spina Bifida Patients: A Pilot Crossover Study

To compare the effects of obybutynin and tolterodine in neurogenic bladder patients with spina bifida in a crossover study.

Seven myelomeningocele and one spinal lipoma cases, maintained with obybutynin and clean intermittent catheterization for more than 60 months, were enrolled. Age ranged from 8 to 23 years (mean 12.0, male/ female = 2/6). After 2 weeks of washout period, obybutynin (0.3 mg/kg, maximum 12 mg) or tolterodine (0.12 mg/kg, maximum 4 mg) was administered for 4 weeks, and then switched to the other drug for 4 weeks. At the end of the three periods, the patients and/or parents documented urinary storage status and adverse effects, and urodynamic study was performed.

In seven cases undergoing sequential urodynamic study, the baseline compliance of the patients (6.81 ± 1.83) increased to 9.98 ± 4.97 by obybutynin and 10.16 ± 2.53 by tolterodine (P < 0.05 for each). Better compliance was noted in two cases with tolterodine and in two cases with obybutynin. Stronger adverse effects were reported in three out of eight patients (37.5%) by obybutynin and three out of eight patients (37.5%) by tolterodine. Although storage effect and side effects were equivalent for total patients, markedly diverse response was noted for each patient, with five choosing tolterodine and three choosing obybutynin.

Individualized evaluation is required for optimal choice of anticholinergics.