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Jean-Jacques Wyndaele

Publications and source records attributed to Jean-Jacques Wyndaele.

At least 19 recordsLinked to original sources
PubMed2006

Amikacin dosing and monitoring in spinal cord injury patients: variation in clinical practice between spinal injury units and differences in experts' recommendations.

The objective of this article was to determine the current practice on amikacin dosing and monitoring in spinal cord injury patients from spinal cord physicians and experts. Physicians from spinal units and clinical pharmacologists were asked to provide protocol for dosing and monitoring of amikacin therapy in spinal cord injury patients. In a spinal unit in Poland, amikacin is administered usually 0.5 g twice daily. A once-daily regimen of amikacin is never used and amikacin concentrations are not determined. In Belgium, Southport (U.K.), Spain, and the VA McGuire Medical Center (Richmond, Virginia), amikacin is given once daily. Whereas peak and trough concentrations are determined in Belgium, only trough concentration is measured in Southport. In both these spinal units, modification of the dose is not routinely done with a nomogram. In Spain and the VA McGuire Medical Center, monitoring of serum amikacin concentration is not done unless a patient has renal impairment. In contrast, the dose/interval of amikacin is adjusted according to pharmacokinetic parameters at the Edward Hines VA Hospital (Hines, Illinois), where amikacin is administered q24h or q48h, depending on creatinine clearance. Spinal cord physicians from Denmark, Germany, and the Kessler Institute for Rehabilitation (West Orange, New Jersey) state that they do not use amikacin in spinal injury patients. An expert from Canada does not recommend determining serum concentrations of amikacin, but emphasizes the value of monitoring ototoxicity and nephrotoxicity. Experts from New Zealand recommend amikacin in conventional twice- or thrice-daily dosing because of the theoretical increased risk of neuromuscular blockade and apnea with larger daily doses in spinal cord injury patients. On the contrary, experts from Greece, Israel, and the U.S. recommend once-daily dosing and determining amikacin pharmacokinetic parameters for each patient. As there is considerable variation in clinical practice across spinal units and experts differ on ideal dosing and monitoring of amikacin therapy in spinal cord injury patients, there is an urgent need to develop best-practice guidelines.

Amikacin↗
PubMed2006

Does the cystometric filling rate affect the afferent bladder response pattern? A study on single fibre pelvic nerve afferents in the rat urinary bladder.

AIMS: To study the effect of physiological and supraphysiological filling rates on the response pattern of single fibre pelvic nerve afferents of the rat urinary bladder. MATERIALS AND METHODS: A total of 37 single afferent bladder units were identified electrophysiologically and their mechanosensitive properties studied. Afferent activity of 13 units was studied at filling rates of 40 and 200 microl/min. Afferent activity of the other units was studied at 200 and 400 microl/min. RESULTS: At the physiological filling rate of 40 microl/min two clearly different types of response pattern were noted. However, at higher supraphysiological filling rates, all units exhibited nearly the same pattern. The difference in mechanosensitive properties of the units that showed a change in response pattern at the supraphysiological filling rate, was characterized by a decrease in pressure at which afferent firing rate peaked. For all units it was found that an increase in filling rate induced an increase in the activation pressure threshold for afferent units, whereas the afferent firing rate at all pressures decreased. CONCLUSIONS: In rats supraphysiological filling rates delay afferent activation, lower afferent firing activity and even change the characteristics of some afferents completely. These data may elucidate some of the differences between ambulatory and conventional urodynamics observed in man.

Animals↗
PubMed2006

Systemic oxybutynin decreases afferent activity of the pelvic nerve of the rat: new insights into the working mechanism of antimuscarinics.

AIMS: In a rat model, intravesical oxybutynin was recently shown to suppress pelvic afferent nerves. This study evaluates if a similar effect exists after systemic administration of oxybutynin. METHODS: Twenty-four single afferent bladder nerves were identified in 15 rats. Based on their conduction velocities they were grouped as C or Adelta fibers. Bladder filling parameters and afferent nerve spike rate were simultaneously recorded 30 min before administration of saline (nine fibers) or oxybutynin (15 fibers, 1 mg/kg), and again 30, 60, 90, 120, and 150 min after systemic saline or drug administration. RESULTS: No change in C or Adelta afferent spike rate was observed after saline injection (P > 0.90). In the study group, a decrease in afferent activity was noted after systemic administration of oxybutynin for C fibers, which were statistically significant 90 (P < 0.004) and 120 min (P < 0.028) after drug delivery. After 150 min, the spike rate was still lower compared to the baseline filling, without reaching the level of significance (P > 0.09). For the Adelta fibers the decrease in afferent spike rate was already significant at 30 min (P < 0.005) and remained significant during all subsequent fillings (P < 0.012). To avoid a possible confounding influence of the bladder compliance, which increased significantly after injection of oxybutynin (P < 0.011), afferent activity during bladder filling was recalculated. Normalized afferent sensitivity of C and Adelta fibers decreased significantly after injection of oxybutynin. This means that the decrease in afferent spike rate is not the result of an increased compliance. CONCLUSIONS: The findings of this study strongly suggest that oxybutynin directly or indirectly influences bladder sensory nerves, inhibiting the afferent part of the micturition reflex.

Animals↗
PubMed2006

Intimate examination teaching with volunteers: implementation and assessment at the University of Antwerp.

OBJECTIVES: Teaching intimate physical examinations in medical schools generates practical, didactical and ethical problems. At the University of Antwerp, a unique program with intimate examination assistants (IEA) was implemented for fifth year's undergraduate students. They learn gynaecological and urological skills in healthy volunteers. Technical, communicative and attitude aspects are taken into account. METHODS: Description of the implementation of the project. Assessment of the project by questionnaires, written reflections and round table conferences. RESULTS: The results provide detailed information about the student's perceptions of each component of the program as well as the perceptions of the IEA's and the teachers. CONCLUSION: The multilevel evaluation of the program supports the surplus value of working with IEA's in medical education. The eye-catcher in this program is the integration of clinical skills with communicative skills and attention for students' attitude. PRACTICE IMPLICATIONS: Working with IEA's for intimate examinations represents a benefit in medical education by lowering the student's threshold to perform the intimate physical examination on both men and women during their fulltime clerkships.

Adult↗
PubMed2006

Healthy, middle-aged, history-free, continent women--do they strain to void?

PURPOSE: We evaluated to what extent abdominal straining is used for voiding in an asymptomatic, continent, healthy, middle-aged female population. MATERIALS AND METHODS: A total of 32 women (mean age 49 +/- 6 years old) could be prospectively included. Technical investigations consisted of flowmetry, pressure flowmetry with EMG and electrosensation evaluation. Some data were compared with those of stress incontinent women investigated prospectively in the same way. RESULTS: There were 4 women who were excluded from analysis because of abnormal sensory evaluation. The symptom-free participants voided with low detrusor pressure, a high flow rate and no residual. A large segment (42%) used additional abdominal straining to void on cystometry and reported that such straining was their usual habit for voiding at home. Straining was seen as frequent in women with stress incontinence. However, significantly more women with stress incontinence used straining without detrusor contraction. CONCLUSIONS: These healthy middle-aged women without a history of pelvic surgery, or symptoms or signs of urological, anorectal or gynecological problems, voided with a mean Pdetmax of 25 cm H(2)O, mean Qmax of 29 ml per second, and the majority without residual. Many of them strained during detrusor contraction and this had not led to the development of signs or symptoms. The way straining is done may make the difference in that during reflex bladder contraction and urethral relaxation, additional straining may have little negative effect. If straining is used to void without the initiation of the micturition reflex, voiding dysfunction and incontinence might develop more easily.

Adult↗
PubMed2005

Dose response with darifenacin, a novel once-daily M3 selective receptor antagonist for the treatment of overactive bladder: results of a fixed dose study.

This study evaluated the efficacy, tolerability, and safety of darifenacin, an M3 selective receptor antagonist (M3 SRA), in patients with overactive bladder (OAB). In a multicenter, double-blind, placebo-controlled dose-ranging study, 439 adult OAB patients (85.4% female) were randomized to darifenacin controlled-release tablets 7.5 mg (n = 108), 15 mg (n = 107) or 30 mg (n = 115) qd, or placebo (n = 109) for 12 weeks. Darifenacin significantly reduced the median number of incontinence episodes/week (-68.7, -76.5, and -77.3% from baseline at 7.5, 15, and 30 mg, respectively, vs -46% with placebo, all p < 0.01) and dose relatedly improved micturition frequency, frequency and severity of urgency, nocturia, and bladder capacity. Darifenacin was well tolerated. Adverse events were commonly mild to moderate dry mouth and constipation. There were no safety concerns. Darifenacin is effective and well tolerated in the treatment of OAB, with 7.5 and 15 mg doses offering flexibility of dosing for optimal treatment outcome.

Adult↗
PubMed2005

Current perception thresholds in the lower urinary tract: Sine- and square-wave currents studied in young healthy volunteers.

AIMS: To establish normative current perception threshold (CPT) values with neuroselective sine-wave current in the lower urinary tract and to compare these values with square-wave current CPTs. MATERIALS AND METHODS: 10 female and 8 male healthy volunteers were used for this study. A filling cystometry was performed and CPTs were determined with square-wave current at a frequency of 2.5 Hz and with neuroselective sine-wave current at 5 (C-fiber), 250 (Adelta-fiber), and 2000 Hz (Abeta-fiber) in the bladder, the posterior, and the distal urethra. RESULTS: Bladder CPTs were significantly higher compared with CPTs in the posterior urethra (P < 0.028) and in the distal urethra (P < 0.002) with all three sine-wave frequencies. No significant difference was found with any sine-wave frequency between the posterior and distal urethra (P > 0.30). Using square-wave pulses at 2.5 Hz, CPTs decreased towards the distal urethra, with a significant difference between the three stimulation sites (P < 0.0001). At all sites tested, the CPT's determined with sine-wave current at 2000 Hz were significantly higher than those at 250 Hz (P < 0.002) and 5 Hz (P < 0.001). No significant difference was found between 5 Hz and 250 Hz at any site in the LUT (P > 0.50). At all sites, CPTs determined with square-wave pulses at 2.5 Hz were significantly higher than those determined with sine-wave current at all frequencies (P < 0.001). CPTs determined with all sine-wave currents were not correlated with CPTs using square-wave pulses. There was no correlation between the volumes at which sensation of filling occurred and the CPTs. CONCLUSIONS: We described normative values in young healthy volunteers at three sites in the LUT using sine-wave current. Although this type of current is said to be neuroselctive, this needs to be confirmed. Stimulation with sine-wave current is different and might be more physiologic compared to square-wave stimulation. Our data show that sine-wave current stimulation at 5 Hz, 250 Hz, and 2000 Hz can probably not be used as a semi-objective measurement of the sensation of bladder filling because no correlation was found between CPTs and the cystometeric sensation of filling.

Adult↗
PubMed2005

Treatment of overactive bladder in the older patient: pooled analysis of three phase III studies of darifenacin, an M3 selective receptor antagonist.

AIM: To evaluate the efficacy, tolerability and safety of darifenacin, an M(3) selective receptor antagonist, in the subgroup of older patients from a pooled analysis of three phase III, multicentre, randomized, double-blind clinical trials in patients with overactive bladder (OAB). PATIENTS AND METHODS: 317 patients aged > or =65 years with OAB symptoms (urge incontinence, urgency and frequency) received up to 12 weeks' oral treatment with darifenacin 7.5 mg or 15 mg once daily or matching placebo. Efficacy was evaluated from daily electronic diary records. Safety endpoints included withdrawal rates and treatment-related adverse events. RESULTS: Darifenacin treatment of patients aged > or =65 years was associated with a dose-related, significant improvement of all the major symptoms of OAB. At week 12, the median reduction in incontinence episodes/week was greater with darifenacin 7.5 mg or 15 mg than in the corresponding placebo arms (66.7% vs. 34.8% and 75.9% vs. 44.8%, respectively, both p < 0.001). Both doses were also significantly superior to placebo in improving micturition frequency (both p < 0.001), bladder capacity (volume voided) (darifenacin 7.5 mg, p = 0.018, darifenacin 15 mg, p < 0.001), and the frequency of urgency episodes (both p < 0.001). Darifenacin was well tolerated. The most common treatment-related adverse events were dry mouth (7.5 mg, 20.6%; 15 mg, 30.9%; placebo, 4.5%) and constipation (7.5 mg, 18.6%; 15 mg, 23.6%; placebo, 6.4%), typically mild or moderate. Use of constipation remedies (laxatives, stool softeners or fibre supplements) was low and similar between groups (7.5 mg, 10.3%; 15 mg, 16.4%; placebo, 10.0%). There were few withdrawals due to treatment-related adverse events (7.5 mg, 1.0%; 15 mg, 9.1%; placebo, 2.7%), and no nervous system or cardiovascular safety concerns. CONCLUSIONS: The results demonstrate excellent efficacy, tolerability and safety with darifenacin 7.5 mg and 15 mg once-daily treatment for OAB in older patients.

Aged↗
PubMed2005

Mitomycin C and epirubicin: functional bladder damage in rats after repeat intravesical instillations.

PURPOSE: We studied functional damage in the bladder after intravesical administration of mitomycin C or epirubicin in rats. MATERIALS AND METHODS: A total of 40 rats were divided into 4 groups. Rats in 3 groups received intravesical instillations of mitomycin C, epirubicin or saline. Rats in group 4 received no intravesical instillations and served as normal controls. The doses of drugs administered were based on those used for therapeutic purposes. Changes in vesical capacity and bladder wall compliance were determined. Compliance was defined as the change in vesical volume induced by a given change in pressure. RESULTS: Weekly instillations of 1 mg/ml mitomycin C caused a statistically significant decrease in vesical volume and compliance, which persisted 3 weeks after the cessation of therapy. Epirubicin also induced changes in vesical volume and compliance but only that in bladder compliance achieved statistical significance. These changes were not seen in NaCl treated animals or in normal controls. CONCLUSIONS: Repeat intravesical instillations of mitomycin C have a prolonged effect on bladder function that is not seen after saline solution or epirubicin instillation.

Administration, Intravesical↗
PubMed2005

Refractory monosymptomatic nocturnal enuresis: a combined stepwise approach in childhood and follow-up into adolescence, with attention to the clinical value of normalizing bladder capacity.

OBJECTIVE: To assess the importance of normalizing bladder capacity to the age-expected capacity in children with refractory monosymptomatic nocturnal enuresis (MNE), and to evaluate the long-term results when these children grow into adolescence. PATIENTS AND METHODS: The study included 34 children with refractory MNE; all were treated > 5 years earlier for their MNE using a combined stepwise approach, consisting of retention control training, oxybutynin and an enuresis alarm. Data were obtained on their enuretic state, night-time voiding behaviour and bladder capacity, from a questionnaire and a voiding chart. RESULTS: Before starting treatment, all patients had a bladder capacity that was too small for their age. After the combined stepwise approach, MNE improved in all patients and 24 (71%) were cured. Although the bladder capacity was increased to the age-expected capacity in 26 (76%), most woke at night to void. Currently, at a mean of 7.7 years after the primary treatment, 28 (82%) of the patients are completely dry at night, of whom 15 (54%) arouse to void for 35% of the nights. Six patients (18%) still have some enuretic episodes. Only those who were dry after primary treatment and remained dry had a normal age-expected increase in bladder capacity. For all others there was a decrease in age-related bladder capacity. CONCLUSIONS: In patients with refractory MNE, a combined stepwise approach improves and may even eliminate enuresis, but normal night-time bladder behaviour in adolescence and adulthood is only achieved in some. Furthermore, about a fifth still have some enuretic episodes.

Adolescent↗
PubMed2004

A normal flow pattern in women does not exclude voiding pathology.

It is a widespread assumption that normal micturition behaviour is reflected in a normal flow pattern. This would also mean that a normal flow curve would correspond with normal voiding and would even permit to exclude voiding difficulties. In our study we investigated the value of a normal flow pattern in four different groups: stress incontinent women, women with bladder overactivity, healthy middle-aged volunteers and healthy students. These women voided with a bell-shaped flow curve on pressure flow in 50, 65, 57 and 50%, respectively. Women who strained to void, a major component of dysfunctional voiding, managed to void a bell-shaped flow curve in 46, 60, 70 and 100%, respectively. Our study demonstrates that a "normal" bell-shaped flow curve does not exclude voiding dysfunction in women.

Adult↗
PubMed2004

Risk factors for recurrent urinary tract infection in 4,332 Belgian schoolchildren aged between 10 and 14 years.

UNLABELLED: To analyse the risk factors for recurrent urinary tract infection (UTI) and the possible influence of potty-training, a questionnaire with 41 questions was completed by 4,332 parents of children completing the last 2 years of normal primary school. Statistical analysis was done with the Chi-squared test and Yates correction. Three groups of children emerged: one without any history of UTI ( n=3818), a group with one actual or former UTI ( n=382) and a group with recurrent UTI ( n=132). Mean age was 11.5+/-0.56 years. A strong correlation between daytime and/or night-time wetting, voiding frequency of more than 10 times a day and nocturia and recurrent UTI was found. No correlation between these factors and a single UTI could be demonstrated. In the 343 bed-wetting children, equal infections for boys and girls were found. Potty-training started significantly earlier in children without UTI. Parents of children with recurrent UTIs insisted more when the first attempt to void was unsuccessful: in the group without UTI, most parents just postponed and had the child try later again. In the group with recurrent UTI, more parents asked the child to strain, made special noises or turned on a tap. CONCLUSION: Daytime with/without night-time wetting, more than 10 voidings a day and nocturia are indicators of recurrent urinary tract infections. If they are simultaneously present, the relative risk for recurrent urinary tract infections is 60%. Consequently, paediatricians should take urinary symptoms very seriously into account, and as incontinence is still a hidden condition, question the child on this topic.

Adolescent↗
PubMed2004

Detrusor overactivity. Does it represent a difference if patients feel the involuntary contractions?

PURPOSE: We evaluated the differences between patients with overactive bladder (OAB) who felt involuntary detrusor contractions during cystometry (detrusor overactivity [DO]) and those who did not feel them. MATERIALS AND METHODS: We prospectively studied 45 patients with symptoms of nonneurogenic, nonobstructed overactive bladder and with DO on cystometry. All patients underwent videourodynamics, the ice water test and electrical perception threshold determination. Continence, urodynamic parameters, data from specific sensory evaluation and outcome of drug treatment were examined. RESULTS: Almost half of our patients did feel the contractions of DO and half did not. The groups differed significantly. Those without DO sensation were more frequently incontinent, had more involuntary detrusor contractions and these occurred earlier during bladder filling. They had involuntary start of voiding more frequently, more pathological sensation of bladder filling and lower electrical sensory thresholds. The results of drug treatment were better in the group who felt DO. CONCLUSIONS: Contractions of DO are felt by some of the patients and they differ from those patients who do not feel such contractions. It is likely that this finding reflects the existence of different OAB conditions with a different neuropathological cause and a different treatment outcome. Therefore, we suggest that specific tests for the evaluation of sensation in the lower urinary tract should be part of the diagnosis of patients with DO and symptoms of OAB.

Adult↗
PubMed2004

Duloxetine versus placebo in the treatment of European and Canadian women with stress urinary incontinence.

OBJECTIVE: To assess the efficacy and safety of duloxetine in women with stress urinary incontinence. DESIGN: Randomised double-blind, placebo-controlled clinical trial. SETTING: Fort-six centres in seven European countries and Canada. POPULATION: Four hundred and ninety-four women aged 24-83 years identified as having predominant symptoms of stress urinary incontinence using a clinical algorithm that was 100% predictive of urodynamic stress urinary incontinence in a subgroup of 34 women. METHODS: The case definition included a predominant symptom of stress urinary incontinence with a weekly incontinence episode frequency > or =7, the absence of predominant symptoms of urge incontinence, normal diurnal and nocturnal frequencies, a bladder capacity > or =400 mL and both a positive cough stress test and positive stress pad test. Subjects completed two urinary diaries prior to randomisation and three diaries during the active treatment phase of the study, each completed during the week prior to monthly visits. Subjects also completed quality of life questionnaires at each visit. Safety was assessed by the evaluation of treatment-emergent adverse events, discontinuation of treatment because of adverse events, serious adverse events, vital sign measurements, electrocardiograms (ECG) and clinical laboratory tests. INTERVENTION: After a two-week placebo lead-in, women received placebo or duloxetine 40 mg BD for 12 weeks. MAIN OUTCOME MEASURES: The percentage decrease in incontinence episode frequency and the change in the Incontinence Quality of Life (I-QOL) questionnaire total score were prespecified as co-primary outcome variables in the protocol. RESULTS: Incontinence episode frequency decreased significantly with duloxetine compared with placebo (median decrease of 50%vs 29%; P= 0.002) with comparable improvements in the more severely incontinent subgroup (those experiencing at least 14 incontinence episodes per week at baseline; 56%vs 27% decreases; P < 0.001). The primary analysis of I-QOL scores did not reveal a significant difference between treatment groups, due primarily to the carrying forward of low scores from patients who discontinued treatment very early due to duloxetine-associated adverse events. The increase in I-QOL scores was significantly greater for duloxetine than for placebo at each of the three postrandomisation visits after 4, 8, and 12 weeks of treatment. Discontinuation rates for adverse events were higher for duloxetine (22%vs 5%; P < 0.001) with nausea being the most common reason for discontinuation (5.3%). Nausea tended to be mild to moderate, not progressive, and transient. CONCLUSIONS: The findings support duloxetine as a potential treatment for women with stress urinary incontinence.

Adult↗
PubMed2003

Frequency-volume charts: a tool to evaluate bladder sensation.

AIMS: Bladder sensation is routinely evaluated by cystometric bladder filling and electrical stimulation. These methods require catheterization and stimulate the bladder artificially. In this study, we evaluated whether frequency-volume charts can be used as a non-invasive tool to study bladder sensation during normal daily life. Furthermore the agreement between sensory data obtained from frequency-volume charts and conventional cystometric bladder filling is studied. MATERIALS AND METHODS: Fifteen healthy female students filled out frequency-volume charts at home and scored the grade of perception of bladder fullness at each micturition. They also measured the volume of three voidings after postponing micturition as long as possible. Sensation of bladder filling was finally evaluated during cystometry. RESULTS: On frequency-volume charts, 65% of all voidings was made without desire to void, only 9.5% was with strong desire. Urgent desire to void was not reported except after voluntarily postponing micturition. Higher grades of perception of fullness were associated with significantly higher voided volumes. Mean volumes for the different sensations of fullness on the charts were not significantly different from volumes at different sensations reported during cystometry. CONCLUSIONS: In conclusion, bladder sensation during daily life can be evaluated by scoring the grade of perception of fullness on frequency-volume charts. During life voiding usually occurs without desire to void. The voided volumes at different sensations of fullness are comparable to the volumes at different sensations of filling during cystometry. Therefore, frequency-volume charts with evaluation of perception of fullness may provide an initial non-invasive tool to study bladder sensation.

Adolescent↗
PubMed2003

Functional bladder capacity after bladder biofeedback predicts long-term outcome in children with nocturnal enuresis.

OBJECTIVE: We previously reported a 70% cure rate for bladder biofeedback in children with primary nocturnal enuresis associated with small bladder capacity and detrusor instability. In this paper we report on bladder capacity and incidence of enuresis after 60 months of follow-up and discuss the role of decreased bladder capacity in nocturnal enuresis. MATERIAL AND METHODS: We prospectively evaluated 21 boys and 3 girls (mean age 10.4 years) treated with bladder biofeedback between October 1993 and July 1995. Baseline bladder capacity and capacity at the end of treatment and at 60 months follow-up were determined from a micturition chart. RESULTS: At the end of primary treatment 17/24 patients had stopped bedwetting. In 4/17 responders and 4/7 non-responders the bladder capacity was <90% of normal for age. At 60 months, 4 patients had been lost to follow-up, 15 were dry at night and 4 continued bedwetting. One patient underwent surgery and was excluded from the study. Only 2/15 dry patients but 3/4 patients with persistent nocturnal enuresis had a bladder capacity of <90% of normal. CONCLUSIONS: Bladder biofeedback can be successfully used to treat children with refractory nocturnal enuresis associated with small bladder capacity and unstable detrusor. Normalization of bladder capacity and continuous growth of the bladder in order to keep the capacity normal would seem to be crucial to the long-term resolution of bedwetting in this select patient population.

Biofeedback, Psychology↗
PubMed2003

Intravesical oxybutynin: a local anesthetic effect on bladder C afferents.

PURPOSE: Intravesical oxybutynin is used to control bladder overactivity in patients who are refractory to or cannot tolerate oxybutynin given orally. Although it is clinically effective, the mode of action of intravesical oxybutynin remains unclear. We tested the influence of intravesical oxybutynin on single fiber pelvic nerve afferents from the rat bladder. MATERIALS AND METHODS: A total of 15 single afferent bladder units were identified. Based on conduction velocity they were grouped as Adelta or C fibers. The effect of repeat bladder filling was studied on the mechanosensitive properties of these units. Oxybutynin was than instilled and left in the bladder for 15 minutes. Unitary afferent activity was again analyzed 15, 60 and 90 minutes after the drug was removed. RESULTS: Repeat bladder filling did not change nerve activity in Adelta or C fibers. At 15 minutes after oxybutynin was washed out of the bladder C fiber afferents responded significantly less to intravesical pressure and volume compared with control filling. At 60 minutes C fibers partly regained mechanosensivity. After 90 minutes sensitivity still increased without achieving the response level before oxybutynin. No significant changes were noted in Adelta fibers during repeat bladder filling or after oxybutynin instillation. CONCLUSIONS: In this study we showed that intravesical oxybutynin has a direct anesthetic effect within the bladder wall. It temporarily desensitizes C fiber afferents, which could explain its clinical benefits in decreasing symptoms of bladder overactivity. No measurable effect was found on Adelta fibers.

Administration, Intravesical↗