Objective: To compare tolterodine with oxybutynin and placebo in people with neurogenic detrusor overactivity.
Design: Prospective, randomized, double-blind, crossover trial plus open-label comparative stage.
Participants: Ten participants with neurogenic detrusor overactivity due to spinal cord injury or multiple sclerosis who used intermittent catheterization.
Methods: Bladder capacity on cystometrogram, a 10-day record of catheterization volumes, number of incontinent episodes per day, and perceived dry mouth using a visual analog scale (VAS) were measured for the following: (a) a blinded comparison: tolterodine, 2 mg twice daily, vs placebo, twice daily; and (b) an unblinded comparison: oxybutynin vs tolterodine, each at self-selected doses (SSDs).
Results: Tolterodine, 2 mg twice daily, was superior to placebo in enhancing catheterization volumes (P < 0.0005) and reducing incontinence (P < 0.001), but was comparable with placebo in cystometric bladder capacity. Efficacy of tolterodine SSD was comparable with oxybutynin SSD with regard to catheterization volumes, degree of incontinence, and cystometric bladder capacity. The side effect profile (dry mouth) was comparable between tolterodine, 2 mg twice daily, and placebo, but differed significantly when comparing tolterodine SSD with oxybutynin SSD (P < 0.05).
Conclusion: Tolterodine, when used at SSDs, is comparable with oxybutynin at SSDs in enhancing bladder volume and improving continence, but with less dry mouth. Tolterodine at the recommended dosage of 2 mg twice daily improves incontinence and bladder volumes compared with placebo, and without significant dry mouth. Larger doses of tolterodine may be needed to achieve best effect in this population, but further studies are required.