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Updated: Aug 19, 2026

Detrusor Underactivity Model in Rats by Conus Medullaris Transection
Published on: August 28, 2020
Resiniferatoxin for detrusor instability refractory to anticholinergics
Paulo C R Palma1, Marcelo Thiel, Cássio L Z Riccetto
1Division of Urology, State University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
Purpose:
We have evaluated the clinical and urodynamic effects of intravesical instillation of resiniferatoxin in patients with idiopathic detrusor instability refractory to anticholinergics.
Materials And Methods:
There were 30 women, median age 56 years old with detrusor instability for over 6 months and a history of anticholinergic use with no response or intolerable collateral effects. A 50 nM solution of resiniferatoxin was prepared for intravesical instillation. All patients were evaluated for urinary symptoms, as well as for urodynamic assessments before and 30 days after instillation. Tolerability was analyzed during the instillation.
Results:
A clinical improvement was observed in 30% of the patients with urinary urgency and in 33% of the patients with urge-incontinence. The mean maximum cystometric capacity before application was 303.9 +/- 78.9 and after application 341 +/- 84.6. No significant difference was observed (p = 0.585). The mean maximum amplitude of the contractions diminished from 47.86 +/- 29.64 to 38.72 +/- 30.77 (p = 0.002).
Conclusions:
Resiniferatoxin, in this concentration, proved to be useful in a small percentage of patients regarding clinical detrusor instability. Maximum amplitude of the involuntary contractions was significantly reduced and in 33% patients the involuntary contractions disappeared. Further studies with different concentrations are recommended.
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