P. Navarra

Intravesical Capsaicin Versus Resiniferatoxin In Patients With Detrusor Hyperreflexia: A Prospective Randomized Study

PURPOSEnCapsaicin and resiniferatoxin (Sigma Chemical Co., St. Louis, Missouri) administered intravesically are attractive options for treating detrusor hyperreflexia. Because the 2 agents differ in chemical structure and relative potency, possible differences in their clinical and urodynamic effects were investigated in this prospective comparative study.nnnMATERIALS AND METHODSnA group of 24 spinal cord injured patients with refractory detrusor hyperreflexia were randomly assigned to receive a single dose of 2 mM. capsaicin in 30 ml. ethanol plus 70 ml. 0.9% sodium chloride or 100 nM. resiniferatoxin in 100 ml. 0.9% sodium chloride. Dwell time was 40 minutes with urodynamic monitoring. Urodynamics were performed at baseline before treatment, and after followups of 30 and 60 days. The frequency of daily catheterizations, incontinence episodes and side effects was recorded.nnnRESULTSnThere was no significant urodynamic or clinical improvement in the capsaicin arm at 30 and 60 days of followup. In the resiniferatoxin arm the mean uninhibited detrusor contraction threshold plus or minus standard deviation increased from 176 +/- 54 to 250 +/- 107 ml. at 30 days (p <0.05) and to 275 +/- 98 ml. at 60 days (p <0.01). Mean maximum bladder capacity increased from 196 +/- 75 to 365 +/- 113 ml. at 30 days (p <0.001) and to 357 +/- 101 ml. at 60 days (p <0.001). Daily catheterizations and incontinent episodes were significantly decreased at 30 and 60 days of followup. Autonomic dysreflexia, limb spasms, suprapubic discomfort and hematuria developed in most patients who received capsaicin but in none who received resiniferatoxin.nnnCONCLUSIONSnIntravesical administration of resiniferatoxin is superior to that of capsaicin in terms of urodynamic results and clinical benefits in spinal cord injured patients and it does not cause the inflammatory side effects associated with capsaicin.

INTRAVESICAL ELECTROMOTIVE ADMINISTRATION OF OXYBUTYNIN IN PATIENTS WITH DETRUSOR HYPERREFLEXIA UNRESPONSIVE TO STANDARD ANTICHOLINERGIC REGIMENS

PURPOSEnAbout 15% to 20% of patients with detrusor hyperreflexia do not benefit from oral oxybutynin regimens, frequently because of unpleasant side effects. Several reports indicate that intravesical oxybutynin is effective in many of these patients but there are some who still fail to respond.nnnMATERIALS AND METHODSnA select group of 10 adults with detrusor hyperreflexia unresponsive to standard oral and intravesical oxybutynin regimens were treated at weekly intervals with 5 mg. oxybutynin orally, or 5 mg. oxybutynin in 100 ml. intravesically for 60 minutes of passive diffusion and for 30 minutes with 5 mA. electrical current. Each treatment (plus oral placebo and 2 intravesical controls) was associated with an 8-hour, full urodynamic monitoring session, and periodic blood and bladder content sampling.nnnRESULTSnThere was no significant objective improvement with oral or intravesical passive diffusion oxybutynin. Conversely there was significant improvement in 5 of 6 objective urodynamic measurements with intravesical electromotive oxybutynin. Plasma profiles were a single peak and decay following oral oxybutynin and 2 distinct peaks with intravesical passive diffusion and electromotive oxybutynin. Area under the curve for intravesical passive diffusion were 709 ng. per 8 hours versus oral 1,485 (p <0.05) versus intravesical electromotive 2,781 (p <0.001). Bladder content samples confirmed oxybutynin absorption. Oral oxybutynin caused anticholinergic side effects in 7 of 10 patients. There were no side effects with intravesical passive diffusion or electromotive administrations.nnnCONCLUSIONSnAccelerated intravesical administration results in greater bioavailability and increased objective benefits without side effects in previously unresponsive patients compared with oral and intravesical passive diffusion oxybutynin administration.

INTRAVESICAL OXYBUTYNIN: MODE OF ACTION ASSESSED BY PASSIVE DIFFUSION AND ELECTROMOTIVE ADMINISTRATION WITH PHARMACOKINETICS OF OXYBUTYNIN AND N-DESETHYL OXYBUTYNIN

PURPOSEnA proportion of patients with detrusor hyperreflexia who are unresponsive to oral oxybutynin often benefit from intravesical oxybutynin instillation. To our knowledge the precise mode of action of this method is obscure.nnnMATERIALS AND METHODSnIn 12 patients with detrusor hyperreflexia who were previously unresponsive to oral and intravesical passive diffusion of 5 mg. oxybutynin we administered 5 mg. oxybutynin orally as well as increased doses of 15 mg. oxybutynin intravesically with passive diffusion and with 15 mA. associated electric current. Each administration mode per patient was associated with an 8-hour urodynamic monitoring session during which oxybutynin and N-desethyl oxybutynin plasma levels, and intravesical oxybutynin uptake were measured.nnnRESULTSnA dose of 5 mg. oxybutynin orally induced no urodynamic improvement with an area under the plasma concentration time curve of combined N-desethyl oxybutynin plus oxybutynin of 16,297 ng./8 hours and an area under the curve ratio of N-desethyl oxybutynin-to-oxybutynin of 11:1. Passive diffusion oxybutynin resulted in 12 mg. oxybutynin intravesical uptake and significant improvement in 3 of 8 urodynamic measurements, although the area under the curve of combined N-desethyl oxybutynin plus oxybutynin was only 2,123 ng./8 hours and the N-desethyl oxybutynin-to-oxybutynin ratio was 1.1:1.0. Electromotive administration of oxybutynin resulted in almost complete intravesical uptake of the 15 mg. dose, significant improvement in all 8 urodynamic measurements and an increased oxybutynin level versus oral and passive diffusion, although the area under the curve of combined N-desethyl oxybutynin plus oxybutynin was 4,574 ng./8 hours and the N-desethyl oxybutynin-to-oxybutynin ratio was inverted at 1.0:1.4. The oral dose of 5 mg. oxybutynin caused anticholinergic side effects in 8 of the 12 patients. Neither intravesical passive diffusion nor electromotive administration caused side effects with an uptake of 12 and 15 mg., respectively.nnnCONCLUSIONSnA large proportion of intravesical oxybutynin is sequestered, probably in the urothelium. Intravesical oxybutynin administration confers therapeutic benefits via localized direct action within the bladder wall.

Long term follow up of resiniferatoxin intravesical administration in the treatment of detrusor hyperreflexia in spinal cord injured patients

MATERIAL & METHODS: Eleven patients were included in this prospective study. After a basal evaluation with urodynamics and the frequency of daily incontinent episodes, patients received intravesical administrations of RTX 0.6 mM in 50 ml of normal saline. RTX instillations were repeated when there was recurrence of urinary symptoms and/or urodynamic worsening. Uninhibited detrusor contractions (UDC) threshold and maximum pressure, and maximum bladder capacity were measured at baseline and during follow up. The frequency of daily incontinent episodes was recorded by means of a voiding diary. Local or systemic side effects were also noted.