The effects of capsaicin on the neurogenic hyperreflexic detrusor. A double blind placebo controlled study in patients with spinal cord disease. Preliminary results

Abstract

Purpose:Several recent open studies have provided encouraging results as to the e cacy of intravesical installations of capsaicin for neurogenic hyperre¯ectivity. The present trial was performed to verify these results under controlled conditions. Intravesical installation of capsaicin represents a new therapeutic hope for the treatment of the neurogenic hyperrelfexic bladder. Method: This randomized, double-blind study compared the results of the intravesical installation of 30 mg capsaicin in 100 ml of 30% alcohol (experimental group) with those of installing 100 ml 30% alcohol alone (control group). On day 0 and day 30, urodynamic and biopsic examinations were performed in all subjects of each group. Patients: All the subjects included in the study had a functionally disabling form of neurogenic hyperre¯exic bladder resistant to the usual therapies. Cystoscopy and retrograde cystography were performed to exclude any patient who presented with a tumor-like lesion or had vesicoureteral re¯ux. Results: Twelve paraplegic of tetraplegic subjects, seven women and ®ve men whose average age was 46, were included. Eight had multiple sclerosis, and four had sustained a traumatic spinal cord injury. The patients were randomly separated into two groups of six. Initially, there was no clinical or urodynamic di erences in these groups. Installation immediately triggered side e ects and during the ®rst 7 days (suprapubic burning sensation, sensory urgency, hot¯ushes, autonomic hyperre¯exia, hematuria) in ®ve of the six subjects in both groups. Bladder biopsy revealed no signi®cant deterioration. On day 30, there was improvement in all of the experimental-group of patients with signi®cant regression of leakage (P=0.002) and of sensory urgency (P=0.01). Only one control subject had amelioration. Urodynamic examination showed a rise in bladder capacity from 172.5 to 312.3 ml in the experimental group, signi®cantly greater (P=0.03) than the rise from 129 to 175.3 ml observed in the control group. Conclusion: This trial fully con®rms the e cacy of intravesical installations of capsaicin, an e cacy obtained at the cost of nonnegligible side e ects. An intermediate-term follow-up of this treatment will be necessary before considering more widespread use of this agent.

Intravesical Instillation of Capsaicin in Urology: A Review of the Literature

“…While most authors used 30% ethanol as the vehicle for capsaicin [3, 5, 6, 8, 9, 10, 13], others used 10% ethanol [7]or saline solution [11]instead.…”

“…The indications for instillation of capsaicin were detrusor hyperreflexia in five studies [5, 6, 7, 8, 10], hypersensitive bladder disorders or pain of the lower urinary tract in three [2, 4, 11], and either detrusor hyperreflexia or hypersensitive bladder disorder in two [3, 9](table 1). …”

“…Only two were randomized placebo-controlled trials [10, 11]. The other eight were open noncontrolled studies [2, 3, 4, 5, 6, 7, 8, 9].…”

“…Most of the investigators used the protocol described by Fowler et al [12], but others made changes in pharmacologic or temporal parameters. Four research teams used an unmodified Fowler protocol [3, 6, 9, 10, 13]in which patients were placed in a supine position, a three-lumen catheter was introduced into the bladder, and intravesical anesthesia was obtained by instillation of 40 ml of 2% lidocaine left in place for 20 min. This was then evacuated and a solution containing 100 ml of either 1 (0.3 g/l) or 2 mmol/l of capsaicin dissolved in 30% ethanol in saline was instilled over a 2- to 5-min period according to tolerance.…”

“…This finding was confirmed by subsequent clinical studies. Eight open studies [2, 3, 4, 5, 6, 7, 8, 9]and two randomized placebo-controlled trials [10, 11]have shown the efficacy of intravesical instillation of capsaicin against neurogenic bladder disorders including detrusor hyperreflexia, hypersensitive disorders of the lower urinary tract and severe bladder pain. However, the interpretation of these studies is hampered by the lack of consensus regarding the parameters used to evaluate the tolerance and efficacy of instillations and the diversity of therapeutic protocols.…”