Purpose: We investigated the effectiveness and safety of intravesical resiniferatoxin (Sigma Chemical Co., St. Louis, Missouri) and botulinum-A toxin injections into the detrusor muscle in a group of spinal cord injured patients with neurogenic detrusor overactivity unresponsive to conventional anticholinergic therapy.
Materials and methods: A total of 25 patients were randomly assigned to receive intravesically 0.6 microM resiniferatoxin in 50 ml of 0.9% NaCl or injections into the detrusor muscle of 300 units botulinum A-toxin diluted in 30 ml 0.9% NaCl. Clinical evaluation and urodynamics were performed at baseline, and at 6, 12 and 18 months after treatment.
Results: In both arms there was a significant decrease in catheterization and incontinent episodes, and a significant increase in first detrusor contraction and maximum bladder capacity at 6, 12 and 18-month followup. There were no local side effects with either treatment. Botulinum-A toxin induced a significant decrease in the frequency of daily incontinence episodes (p <0.05), a significant increase in first uninhibited detrusor contraction (p <0.01) in maximum bladder capacity (p <0.01), and a significant decrease in maximum pressure of uninhibited detrusor contractions (p <0.01) compared to resiniferatoxin at 6, 12 and 18-month followup.
Conclusions: In spinal cord injured patients with refractory neurogenic detrusor overactivity, intravesical resiniferatoxin and botulinum-A toxin injections into the detrusor muscle provided beneficial clinical and urodynamic results with decreases in detrusor overactivity and restoration of urinary continence in a large proportion of patients. Botulinum-A toxin injections provided superior clinical and urodynamic benefits compared to those of intravesical resiniferatoxin.