Urodynamic effect of intravesical resiniferatoxin in patients with neurogenic detrusor overactivity of spinal origin: Results of a double-blind randomized placebo-controlled trial

Objectives: To access by a placebo-controlled randomized clinical trial the effect of intravesical resiniferatoxin on the urodynamic parameters of patients with neurogenic detrusor overactivity (NDO) of spinal origin. Methods: Twenty eight patients with spinal NDO were randomised to receive intravesically 50 nM resiniferatoxin dissolved in 10% ethanol in saline (RTX group) or only the vehicle solution (placebo group). Filling cystometries were obtained in each patient at 1 month and 1 week before and at 1 and 3 months after treatment. In a visual analog scale patients were asked to estimate the discomfort induced by treatment. Patients were also persuaded to fill a micturition chart during the 3 days preceding each cystometry. Results: The RTX and placebo groups were homogeneous in what respects the volume to first involuntary detrusor contraction (FDC, 143 +/- 95 ml and 115 +/- 58 ml, respectively, p = 0.3) and maximal cystometric capacity (MCC, 189 +/- 99 ml and 198 +/- 111 ml, respectively, p = 0.8). At the end of the study, mean FDC and MCC in the RTX group, 184 +/- 93 ml and 314 +/- 135 ml, respectively were significantly higher than in the placebo group, 115 +/- 61 ml (p = 0.03) and 204 +/- 92 ml (p = 0.02). In the visual analogue scale discomfort caused by treatment was similar. Only 10 patients in the RTX group and 6 patients in the placebo group completed adequately the micturition chart. Mean frequency and urinary incontinence decreased significantly only in the RTX group. Conclusions: Intravesical RTX is effective in increasing bladder capacity in spinal NDO patients. Such increment might contribute to decrease urinary frequency and incontinence of these patients. (c) 2005 Elsevier B.V. All rights reserved.