Current and future pharmacological treatment for overactive bladder

Efficacy of acupoint application in patients with overactive bladder: A randomized, placebo-controlled pilot trial

OBJECTIVE

Conventional treatments for alleviating the symptoms of Overactive bladder (OAB) have been reported to have limited efficacy and a high rate of side effects. Traditional Chinese medicine (TCM) has been used in Asia countries because of its low side effects and being easy to operate. To confirm the efficacy of acupoint application treatment for alleviating OAB symptoms, a randomized and placebo-controlled pilot trial was conducted in this study.

METHODS

All participants were randomly allocated into a treatment group or control group, receiving either a "Dinggui" acupoint application or placebo treatment for 4 weeks. The outcome measures were OAB symptom scores (OABSS), OAB questionnaire (OAB-q) scores, and TCM syndrome scores. Urine nerve growth factor (NGF) level, NGF normalized to urine creatinine (NGF/Cr), and maximum flow rate (Qmax) were also measured to evaluate the OAB symptoms.

RESULTS

In total, 69 participants were included with 34 in the treatment group and 35 in the placebo-treated group. Treatment with "Dinggui" acupoint application showed a statistically significant decrease in OABSS scores (8.10±1.54 to 3.67±1.77), OAB-q scores (61.43±13.93 to 38.13±15.42), and TCM syndrome scores (15.60±5.98 to 9.20±4.82). The NGF and NGF/Cr were also observed meaningful changes in a decrease from 379.68 to 136.17 pg/ml and from 0.30 to 0.16 pg/mg, respectively. The Qmax value showed a significant increase from 14.40 to 24.05 ml/s.

CONCLUSIONS

Treatment with "Dinggui" acupoint application could be considered an effective and alternative therapy for OAB management. Further studies with larger sample sizes and longer treatment periods are needed to investigate.

Comparison of tramadol and lornoxicam for the prevention of postoperative catheter-related bladder discomfort: a randomized controlled trial

BACKGROUND

Catheter-related bladder discomfort (CRBD is a painful complication of intraoperative urinary catheterization after anaesthesia. We conducted this study to compare the effect of tramadol and lornoxicam for the prevention of postoperative CRBD.

METHODS

One-hundred twenty patients (aged 18-60 years, ASA physical status 1-2, undergoing elective uterine surgery requiring intraoperative urinary catheterization were randomly divided into three groups with 40 patients in each group. Group T received 1.5 mg/kg tramadol, group L received 8-mg lornoxicam, and group C received normal saline. The study drugs were administered intravenously at the end of the surgery. The incidence and severity of CRBD were reported at 0, 1, 2, and 6 h after arrival at the postanaesthesia care unit (PACU).

RESULTS

The incidence of CRBD was significantly lower in groups T and L than in group C at 1, 2, and 6 h after surgery. The incidence of moderate to severe CRBD was also significantly lower in groups T and L than in group C at 0, 1, and 2 h after surgery. The severity of CRBD reported as mild, moderate, and severe was reduced in groups T and L compared with group C at most times after surgery. Group T had a higher incidence of nausea than group C, and there were no differences in dizziness, drowsiness, or vomit among the three groups.

CONCLUSIONS

Tramadol and lornoxicam administered intravenously at the end of the surgery were both effective in preventing the incidence and severity of CRBD after uterine surgery. However, tramadol increased the incidence of nausea compared with saline, but there was no difference between tramadol and lornoxicam.

TRIAL REGISTRATION

ChiCTR2100052003. Registered on 12/10/2021.

A time-course study of urodynamic analyses in rat models with dopaminergic depletion induced through unilateral and bilateral 6-hydroxydopamine injections

BACKGROUND

Bladder dysfunction is a common non-motor disorder in Parkinson's disease (PD). This study attempted to determine the bladder dysfunction with disease progression in the PD rat model produced from unilateral/bilateral injections of 6-hydroxydopamine (6-OHDA).

METHODS

Cystometrographic (CMG) and external urethral sphincter electromyographic (EUS-EMG) measurements were scheduled in a time-course manner to determine the disease timing, onset, and severity. Animals were allotted into normal control, unilateral, bilateral 6-OHDA injected groups and subjected to scheduled CMG, EUS-EMG analyses at weeks 1, 2, and 4.

RESULTS

The urodynamic results concluded that voiding efficiency (VE) was reduced in both unilateral and bilateral PD rats at all-time points. VE had decreased from 57 ± 11% to 31 ± 7% in unilateral PD rats and in bilateral PD rats, a decreased VE of 20 ± 6% was observed compared to control and unilateral PD rats. The EMG results in unilateral PD rats indicated declines in bursting period (BP) (3.78-2.94 s), active period (AP) (93.38-88.75 ms), and silent period (SP) (161.62-114.30 ms). A sudden reduction was noticed in BP (3.62-2.82 s), AP (92.21-86.01 ms), and SP (128.61-60.16 ms) of bilateral PD rats than in control and unilateral PD rats. Histological evidence exhibited a progressive dopaminergic neurons (DA) depletion in the substantia nigra (SN) region in 6-OHDA lesioned rats.

CONCLUSION

The experimental outcomes strongly implied that significant variations in bladder function and VE decline were due to the depletion of DA neurons in the SN region of the brain.

Personalised 3D-Printed Mucoadhesive Gastroretentive Hydrophilic Matrices for Managing Overactive Bladder (OAB)

Overactive bladder (OAB) is a symptomatic complex condition characterised by frequent urinary urgency, nocturia, and urinary incontinence with or without urgency. Gabapentin is an effective treatment for OAB, but its narrow absorption window is a concern, as it is preferentially absorbed from the upper small intestine, resulting in poor bioavailability. We aimed to develop an extended release, intragastric floating system to overcome this drawback. For this purpose, plasticiser-free filaments of PEO (polyethylene oxide) and the drug (gabapentin) were developed using hot melt extrusion. The filaments were extruded successfully with 98% drug loading, possessed good mechanical properties, and successfully produced printed tablets using fused deposition modelling (FDM). Tablets were printed with varying shell numbers and infill density to investigate their floating capacity. Among the seven matrix tablet formulations, F2 (2 shells, 0% infill) showed the highest floating time, i.e., more than 10 h. The drug release rates fell as the infill density and shell number increased. However, F2 was the best performing formulation in terms of floating and release and was chosen for in vivo (pharmacokinetic) studies. The pharmacokinetic findings exhibit improved gabapentin absorption compared to the control (oral solution). Overall, it can be concluded that 3D printing technology is an easy-to-use approach which demonstrated its benefits in developing medicines based on a mucoadhesive gastroretentive strategy, improving the absorption of gabapentin with potential for the improved management of OAB.

Urethral monopolar cauterization: alternative infravesical obstruction model in male rats

OBJECTIVE:

We aimed to determine which method gives the most consistent results between urethral monopolar cauterization and standard urethral partial ligation methods for the urethral obstruction model.

METHODS:

Thirty male rats were randomly divided into control, partial ligation, and monopolar cauterization groups. Six weeks after experimental procedures, the experimental groups were evaluated cystometrically, biochemically, and histologically.

RESULTS:

According to the cystometric results, bladder capacity, baseline bladder pressure, and compliance data of the monopolar cauterization group were higher than those of the partial ligation and monopolar cauterization groups (p<0.05 and p<0.01, respectively). As a biochemical evaluation, malondialdehyde levels in bladder tissues of group control were higher than partial ligation and monopolar cauterization groups (p<0.05 and p<0.01, respectively). The collagen type I level of the control group was higher than the partial ligation and monopolar cauterization groups (p<0.01 and p<0.05, respectively). Collagen type III levels of the monopolar cauterization group were higher than those of the control group (p<0.01), but the Collagen type I/Collagen type III and transforming growth factor-β levels of the monopolar cauterization group were significantly lower than those of the control group (p<0.001). As a histological evaluation (hematoxylin and eosin), fibrosis in the lamina propria was more prominent in the monopolar cauterization group than in the control group (p<0.05). In addition, the muscular thickness was higher in the monopolar cauterization group compared with control and partial ligation groups (p<0.001 and p<0.01, respectively).

CONCLUSION:

The needle-tipped monopolar cauterization of the posterior urethra may be the method of choice for creating a chronic infravesical obstruction model of infravesical obstruction in male rats.

Catheter-Related Bladder Discomfort: How Can We Manage It?

The urethral catheter is used in various clinical situations such as diagnosing urologic disease, urine drainage in patients after surgery, and for patients who cannot urinate voluntarily. However, catheters can cause numerous adverse effects, such as catheter-associated infection, obstruction, bladder stones, urethral injury, and catheter-related bladder discomfort (CRBD). CRBD symptoms vary among patients from burning sensation and pain in the suprapubic and penile areas to urinary urgency. CRBD significantly reduces patient quality of life and can lead to several complications. CRBD is caused by catheter-induced bladder irritation due to muscarinic receptor-mediated involuntary contractions of bladder smooth muscle and also can be caused by mechanical stimulus of the urethral catheter. Various pharmacologic studies for managing CRBD, including antimuscarinic and antiepileptic agents and botulinum toxin injections have been reported. If urologists can reduce patients’ CRBD, their quality of life and recovery can improve.

Overactive bladder syndrome - focus onto detrusor overactivity

INTRODUCTION AND HYPOTHESIS

To determine in patients with overactive bladder (OAB), urodynamic differences as well to compare the characteristics of patient's, with presence of detrusor overactivity on urodynamics with those with absence of detrusor overactivity.

METHODS

Taking into account the urodynamic findings, the patients with OAB symptoms were categorized into one of two groups: group 1 (with detrusor overactivity) or group 2 (without detrusor overactivity), and comparative analyses for both groups were performed (epidemiological data, patient history, urodynamic criteria, bladder diaries, IC-OAB, IC-OABqol - questionnaires).

RESULTS

There was a significant difference in age as well in the disease duration between group 1 and group 2. Although the mean number of micturitions and nocturia episodes was comparable, the numbers of urgency episodes differed significantly. The number of 'wet' patients was significantly higher in the group 1 with the significantly higher number of incontinence episodes. Group 1 demonstrated higher OAB symptom scores and higher impact on the patients' quality of life.

CONCLUSIONS

More than half of the patients complaining of urgency-frequency do not have detrusor overactivity upon urodynamic testing, and only half have detrusor overactivity that correlates with urge perception. The patients with no detrusor overactivity appear to be significantly younger and have fewer symptoms, with a less pronounced impact on quality of life. They also have significantly higher maximal bladder capacity. This data supports the hypothesis that both conditions are different phases (early and late) of the same pathological state, or may be two different subtypes of OAB.

Cannabinoids in Urology. Which Benign Conditions Might They Be Appropriate to Treat: A Systematic Review

There is growing evidence suggesting cannabinoids may provide suitable alternatives to conventional treatments in an increasing number of clinical settings. This review evaluates how cannabinoids are used to treat certain benign urological pathologies and to clarify the clinical value of this data. This review includes 62 papers and was undertaken per PRISMA's guidelines, it evidences the therapeutic potential of cannabinoids in the management of specific benign urological diseases, most notably neurogenic bladder dysfunction (clinical studies), renal disease (animal studies), and interstitial cystitis (animal studies). However, whilst cannabinoids are increasingly used, they cannot be considered reliable alternatives to more recognised treatments.

Anesthetic considerations for urologic surgeries

Urologic surgeries are widely performed, and the cases have increased owing to the fact that the elderly population is growing. The narrow and limited surgical space is a challenge in performing most urologic surgeries. Additionally, the elderly population is exposed to the risk of perioperative complications; therefore, a comprehensive understanding and approach are required to provide optimized anesthesia during surgery. We have searched the literature on anesthesia for urologic surgeries and summarized the anesthetic considerations for urologic surgeries.

Gabapentin-Induced Urinary Incontinence: A Rare Side Effect in Patients with Neuropathic Pain

Gabapentin is a first-line agent for neuropathic pain management and has a favorable safety profile. The literature includes a few cases of gabapentin-induced incontinence, and most of them involved patients with epilepsy who were between the ages of 12 and 43 years. Herein, we present three patients with neuropathic pain due to different diagnoses, and, to our knowledge, these are the oldest reported cases of urinary incontinence caused by gabapentin therapy. A 56-year-old female patient who underwent hip arthroplasty developed a sciatic nerve injury and neuropathic pain postoperatively. Ten days after she began taking gabapentin to relieve her pain, she experienced daily urinary incontinence. In another instance, a 63-year-old female patient was diagnosed with complex regional pain syndrome, and seven days after the initiation of gabapentin therapy, urinary incontinence developed. In addition, a 66-year-old male patient with neuropathic pain due to cervical disc pathology complained of urinary incontinence after the onset of gabapentin therapy. After discontinuing this drug, the incontinence symptoms resolved in these patients on the seventh, the first, and the second days, respectively. Physicians who administer gabapentin should inform their patients about the potential risk of gabapentin-induced incontinence and its negative impact on quality of life.

Should we use the shorter Thai-version quality of life and symptoms questionnaires in women with overactive bladder?

AIM

The aim of this study was to test: (i) the validation and reliability of the Thai versions of overactive bladder (OAB) questionnaires (the 8-item and 3-item Overactive Bladder Symptoms Score questionnaires [OAB-v8 and OAB-v3, respectively] and the Overactive Bladder Questionnaire [OAB-q]); and (ii) the correlation of the OAB-v8, OAB-v3, and the single-question Quality of Life Questionnaire (1-QoL) to the OAB-q in Thai women with OAB.

MATERIAL AND METHODS

During January to March 2011, 36 Thai women with OAB attending a urogynecology clinic at Chulalongkorn Hospital, Bangkok, Thailand were recruited. All questionnaires were given as a psychometric test twice, 2 weeks apart.

RESULTS

Cronbach's alpha of the OAB-v8 was higher (and above 0.7) than OAB-v3 at both week 0 and week 2. The intraclass correlations (ricc ) were 0.64, 0.85, and 0.97 for the OABV8, OAB-v3, and OAB-q, respectively. The correlation coefficient (r) of OAB-v3 and OAB-q at weeks 0 and 2 (0.40 and 0.49) were lower than those for OAB-v8 and OAB-q at weeks 0 and 2 (0.62 and 0.62). All questions on the OAB-v3 had a lower weighted kappa than OAB-v8. There was no statistically significant difference in the OAB-q score in each level of 1-QoL score at week 0 (P = 0.12) and at week 2 (P = 0.29).

CONCLUSION

The reliability of the OAB-v3 is poorer than that of the OAB-v8. The OAB-v3 is poorer correlated to the OAB-q than to the OAB-v8. A short questionnaire, such as the OAB-v3 and the 1-QoL, has poor reliability and is poorly correlated to the OAB-q and is not recommended as a replacement for the standard questionnaires, such as the OAB-q and the OAB-v8. The OAB-v3 should only be used in large screening populations where there are time limits.

Symptom score change and patient versus doctor satisfaction in overactive bladder before and after anti-muscarinic treatment

AIMS

To evaluate voiding symptoms and questionnaire score change before and after anti-muscarinic treatment and evaluate the correlation of agreement in patient and doctor satisfaction after treatment.

METHODS

Forty women newly diagnosed with overactive bladder (OAB), attending the urogynecology clinic at Chulalongkorn Hospital during April-June 2011 were recruited. Tolterodine 4 mg orally once daily was given for 4 weeks. A voiding diary and Thai version of the OAB questionnaires eight-item Overactive Bladder awareness tool (OAB-v8), Overactive Bladder Symptoms Score (OABSS) and Overactive Bladder QOL (OABq) were completed before and at the end of treatment. At the end of the trial, self-report patient satisfaction, and doctor satisfaction (according to symptom improvement in the voiding diary) were assessed. Student's t-test and weighted kappa coefficients were used in statistical analysis. Sample size was calculated from an OAB questionnaire pilot study with 20% addition for loss to follow up.

RESULTS

All voiding parameters and questionnaire scores (OAB-v8, OABSS and OABq) were improved after treatment. Weighted kappa was only 0.06, between doctor and patient satisfaction.

CONCLUSION

OAB-v8 and OABSS questionnaires can be used as screening and follow-up tools. There is poor agreement between patient and doctor satisfaction. Satisfaction should therefore be measured from the patient's perspective.

The efficacy of pregabalin for prevention of catheter-related bladder discomfort: a prospective, randomized, placebo-controlled double-blind study

OBJECTIVE

The present study evaluated the efficacy of preoperative pregabalin for prevention of catheter-related bladder discomfort.

DESIGN

Prospective, randomized, placebo controlled, double blinded study.

MATERIALS AND METHODS

Sixty patients of either sex undergoing elective spine surgery and requiring urinary bladder catheterization were randomly assigned to two groups. The patients in Group P (pregabalin group) received 150 mg of pregabalin orally 1 h prior to induction of anesthesia with sips of water and the patients in Group C (control group) received placebo. Anesthesia technique was identical in both the groups. Catheter-related bladder discomfort (CRBD) was evaluated on a 4-point scale (1 = no discomfort, 2 = mild, 3 = moderate, 4 = severe), on arrival (0 h) and again at 1, 2, and 6 h postoperatively. Patients were provided patient-controlled analgesia with fentanyl for postoperative pain relief.

RESULTS

The incidence of CRBD was significantly less in the pregabalin group compared with the control group at all time intervals (P < 0.05). The severity of CRBD was reduced in the pregabalin group compared with the control group at all time intervals except 6 h. The postoperative consumption of fentanyl was significantly less in group P, while the sedation score was significantly higher in the group P compared to group C.

CONCLUSION

Pretreatment with pregabalin 150 mg prevents CRBD and also decreases postoperative fentanyl consumption. ClinicalTrials.gov identifier: (ref: CTRI/2013/11/004170).

Neural control of lower urinary tract and targets for pharmacological therapy

Studies on the physiology and pharmacology of the lower urinary tract have brought new information and concepts about the complex neural control of micturition. There are many mechanisms, some proven and others not yet completely understood, in which pharmacological agents may act facilitating the filling, storage, and emptying of the bladder. This review describes the peripheral innervation and the main pathways involved in lower urinary tract control. It also presents potential targets for the treatment of voiding dysfunctions.

Effects of sensory neuron-specific receptor agonist on bladder function in a rat model of cystitis induced by cyclophosphamide

PURPOSE

To investigate the effects of activation of sensory neuron-specific receptors (SNSRs) on cyclophosphamide (CYP) bladder overactivity in rats.

METHODS

Female Sprague-Dawley rats (235-258 g) were used. Rats were injected with either CYP (200 mg/kg, intraperitoneally) or saline (control). Continuous cystometrograms (0.04 ml/min) were recorded 48 h after CYP or saline injection under urethane anesthesia. After stable micturition cycles were established, a selective rat SNSR1 agonist, bovine adrenal medulla 8-22 (BAM8-22), was administered intravenously or intrathecally.

RESULTS

Cyclophosphamide treatment-induced higher baseline pressure and shorter intercontraction intervals compared with the control group. Intravenous administration of BAM8-22 at 10, 30 and 100 μg/kg significantly increased intercontraction intervals in the CYP-treated group. Intrathecal administration of BAM8-22 at 0.03, 0.1 and 0.3 μg also significantly increased intercontraction intervals in the CYP-treated group. Intravenous or intrathecal administration of BAM8-22 did not change baseline pressure or maximum voiding pressure in the CYP-treated group.

CONCLUSIONS

These findings indicate that activation of SNSRs can suppress CYP-induced bladder overactivity, probably due to suppression of bladder afferent activity.

Stimulation of large-conductance calcium-activated potassium channels inhibits neurogenic contraction of human bladder from patients with urinary symptoms and reverses acetic acid-induced bladder hyperactivity in rats

We have analysed the effects of large-conductance calcium-activated potassium channel (BK) stimulation on neurogenic and myogenic contraction of human bladder from healthy subjects and patients with urinary symptoms and evaluated the efficacy of activating BK to relief bladder hyperactivity in rats. Bladder specimens were obtained from organ donors and from men with benign prostatic hyperplasia (BPH). Contractions elicited by electrical field stimulation (EFS) and carbachol (CCh) were evaluated in isolated bladder strips. in vivo cystometric recordings were obtained in anesthetized rats under control and acetic acid-induced hyperactive conditions. Neurogenic contractions of human bladder were potentiated by blockade of BK and small-conductance calcium-activated potassium channels (SK) but were unaffected by the blockade of intermediate calcium-activated potassium channels (IK). EFS-induced contractions were inhibited by BK stimulation with NS-8 or NS1619 or by SK/IK stimulation with NS309 (3µM). CCh-induced contractions were not modified by blockade or stimulation of BK, IK or SK. The anti-cholinergic agent, oxybutynin (0.3µM) inhibited either neurogenic or CCh-induced contractions. Neurogenic contractions of bladders from BPH patients were less sensitive to BK inhibition and more sensitive to BK activation than healthy bladders. The BK activator, NS-8 (5mg/kg; i.v.), reversed bladder hyperactivity induced by acetic acid in rats, while oxybutynin was ineffective. NS-8 did not significantly impact blood pressure or heart rate. BK stimulation specifically inhibits neurogenic contractions in patients with urinary symptoms and relieves bladder hyperactivity in vivo without compromising bladder contractile capacity or cardiovascular safety, supporting its potential therapeutic use for relieving bladder overactivity.

Intravesical liposome and antisense treatment for detrusor overactivity and interstitial cystitis/painful bladder syndrome

Purpose. The following review focuses on the recent advancements in intravesical drug delivery, which brings added benefit to the therapy of detrusor overactivity and interstitial cystitis/painful bladder syndrome (IC/PBS). Results. Intravesical route is a preferred route of administration for restricting the action of extremely potent drugs like DMSO for patients of interstitial cystitis/painful bladder syndrome (IC/PBS) and botulinum toxin for detrusor overactivity. Patients who are either refractory to oral treatment or need to mitigate the adverse effects encountered with conventional routes of administration also chose this route. Its usefulness in some cases can be limited by vehicle (carrier) toxicity or short duration of action. Efforts have been underway to overcome these limitations by developing liposome platform for intravesical delivery of biotechnological products including antisense oligonucleotides. Conclusions. Adoption of forward-thinking approaches can achieve advancements in drug delivery systems targeted to future improvement in pharmacotherapy of bladder diseases. Latest developments in the field of nanotechnology can bring this mode of therapy from second line of treatment for refractory cases to the forefront of disease management.

Changes of neuregulin-1 (NRG-1) expression in a rat model of overactive bladder induced by partial urethral obstruction: is NRG-1 a new biomarker of overactive bladder?

Background

To determine whether neuregulin-1(NRG-1) is a potential new biomarker of overactive bladder (OAB) induced by partial urethral obstruction in a rat model of OAB and to evaluate the urothelium as a therapeutic target of OAB.

Methods

Female Sprague–Dawley rats were separated into three 20-animal groups: normal, OAB, and 5-hydroxymethyl tolterodine (5-HMT)-treated OAB. In the OAB and OAB + 5-HMT groups, the urethra of each animal was partially obstructed; the OAB + 5-HMT group received intravenous 5-HMT for 3 weeks. At the conclusion of the 5-HMT dosing, the rats in each group underwent cystometrography, and the bladders were histologically evaluated. The expression of brain derived-neurotrophic factor (BDNF) and NRG-1 were evaluated in the urothelium.

Results

Compared with the control group, the OAB group showed a markedly increased bladder weight and a significant decrease in the micturition interval and volume; rats in the OAB + 5-HMT group showed decreased bladder weights and an improved micturition interval and volume. BDNF and NRG-1 were expressed at significantly higher levels in the OAB group, and were significantly reduced in the OAB + 5-HMT group compared with the control group.

Conclusions

The study suggests that NRG-1 is a potential new biomarker of OAB; the urothelium might be a therapeutic target for OAB treatment.

Central nervous targets for the treatment of bladder dysfunction

BACKGROUND

The functions of the lower urinary tract, to store and periodically release urine, are dependent on the activity of smooth and striated muscles in the urinary bladder, urethra, and external urethral sphincter. This activity is in turn controlled by neural circuits in the brain, spinal cord, and peripheral ganglia.

AIMS

This paper will review recent advances in our understanding of the pathophysiology of voiding disorders, especially focusing on the central nervous system.

METHODS

Various neurotransmitters, including acetylcholine, norepinephrine, dopamine, serotonin, excitatory and inhibitory amino acids, adenosine triphosphate, nitric oxide, and neuropeptides, have been implicated in the neural regulation of the lower urinary tract.

RESULTS

Injuries or diseases of the nervous system, as well as drugs and disorders of the peripheral organs, can produce voiding dysfunctions such as urinary frequency, urgency, or incontinence.

CONCLUSION

We discuss the potential targets in the central nervous system and new modalities for the treatment of voiding dysfunction.

Gabapentin: a novel drug as add-on therapy in cases of refractory overactive bladder in children

OBJECTIVE

To determine the effectiveness of gabapentin as an add-on therapy in children presenting with overactive bladder (OAB) not responding to conventional anticholinergics.

MATERIALS AND METHODS

Children with refractory OAB were included prospectively from March 2009 to February 2010. The inclusion criterion was persistence of symptoms while on conventional anticholinergics for 6 months. Gabapentin was prescribed as an add-on therapy. The patients were followed 4 weekly with bladder diary and urodynamic study was repeated at 3 months.

RESULTS

There were 31 children, 26 of neurogenic OAB and 5 of non-neurogenic origin. Mean ± SD age was 8.5 ± 5.3 years. Data were analyzed in 30 patients as treatment was terminated in 1 due to adverse effects. Continence improved in 16 (53.3%) patients. Voiding volume improved from 175 ± 90 to 320 ± 110 ml (p<0.03). Objective assessment of OAB symptom relief showed marked improvement (p<0.05). Mean maximum cystometric bladder capacity improved from 210 ± 94 to 360 ± 110 ml (p<0.02). The maximal detrusor contraction decreased from 75 ± 35 to 25 ± 15 cmH(2)O (p<0.02). Fourteen patients (46.7%) failed to respond to gabapentin therapy. These patients had baseline maximum cystometric bladder capacity <60% for age and maximum detrusor contractions >50 cm of water (p<0.03).

CONCLUSIONS

Gabapentin gives moderate results in children with OAB refractory to conventional anticholinergics. In general, the drug is well tolerated with fewer adverse effects.

Inhibitory effect of somatostatin receptor subtype-4 agonist NNC 26-9100 on micturition reflex in rats

OBJECTIVE

To investigate the effects of activation of somatostatin subtype 4 (SST4) on the micturition reflex in rats.

METHODS

Continuous cystometrograms (0.04 mL/min infusion rate) were performed in female Sprague-Dawley rats (242-265 g) under urethane anesthesia. After stable micturition cycles were established, a selective SST4 receptor agonist, NNC 26-9100, was administered intravenously in normal rats or rats pretreated with capsaicin 4 days before the experiments. The micturition parameters were recorded and compared before and after drug administration.

RESULTS

Intravenous administration of NNC 26-9100 (10-300 μg/kg) significantly increased the intercontraction interval in a dose-dependent fashion. Intravenous administration of NNC 26-9100 (10-300 μg/kg) also significantly increased the pressure threshold in a dose-dependent fashion. No significant changes were seen in the baseline pressure, maximum voiding pressure, or postvoid residual urine volume. However, NNC 26-9100-induced increases in the intercontraction intervals and pressure threshold were not seen in rats with C-fiber desensitization induced by capsaicin pretreatment.

CONCLUSION

These results indicate that in urethane-anesthetized rats, activation of the SST4 receptor can inhibit the micturition reflex by suppression of capsaicin-sensitive C-fiber afferent pathways. Thus, the SST4 receptor could be a potential target for the treatment of C-fiber afferent-mediated bladder dysfunction.

Effect of silymarin on bladder overactivity in cyclophosphamide-induced cystitis rat model

The purpose of this study was to investigate the effects of silymarin, a phytotherapeutic agent, on bladder overactivity in a cyclophosphamide (CYP)-induced cystitis rat model. Female Wistar Albino rats received a single intraperitoneal injection of CYP (150 mg/kg) or saline and after 72 h, bladder function was evaluated by in vitro preparations of whole bladders and cystometry with continuous saline infusion under urethane anesthesia. Silymarin or a vehicle was orally given for 7 days in rats. CYP was injected on the 5th day of silymarin or vehicle treatment and then the animals were killed on the 8th day. CYP-treatment dramatically potentiated the basal spontaneous contractions of isolated whole bladders compared to control rats. In anesthetized rats, during continuous infusion cystometry, intercontraction interval (ICI) was significantly shorter, but bladder voiding pressure was not significantly changed in CYP-injected rats compared to control rats. In the CYP-injected group, silymarin treatment significantly decreased the amplitude, frequency (contractions/min) and area under the curve of spontaneous contractions, but failed to change carbachol-induced contraction in isolated whole bladder. Also, silymarin treatment significantly increased the ICI in comparison to the vehicle treatment. In the saline-injected group, no significant changes in the bladder function were observed between the silymarin and vehicle-treated groups. Histopathological examination showed that CYP-induced bladder inflammation tended to be lower in the silymarin+CYP-treated group. In conclusion, the oral administration of silymarin suppressed CYP-induced bladder overactivity. Silymarin may be considered as an attractive treatment for CYP-induced bladder overactivity.

Development and validation of the Chinese Overactive Bladder Symptom Score for assessing overactive bladder syndrome in a RESORT study

BACKGROUND/PURPOSE

This study aimed to develop and validate the Chinese Overactive Bladder Symptom Score (OABSS) for assessing overactive bladder (OAB) symptoms and compare it with a 3-day bladder diary.

METHODS

The Chinese OABSS was developed by linguistic validation of the original version. Its reliability and validity and correlations with a 3-day bladder diary were tested on patients with OAB in a multicenter study conducted in Taiwan (the RESORT study).

RESULTS

A total of 60 patients with OAB, either incontinent (OAB wet, n=31) or continent (OAB dry, n=29), were enrolled consecutively in this study. The test-retest reliability of the Chinese OABSS was moderate to good, with weighted kappa coefficients of 0.515-0.721 for each symptom score and 0.610 for the total symptom score. Each symptom score correlated positively with the total OABSS (Spearman's rho 0.365-0.793) and was internally consistent (Cronbach's alpha 0.674). The distribution of the OABSS showed a clear separation between OAB wet (average 11.4, range 7-15) and OAB dry (average 7.97, range 4-10) subgroups (Wilcoxon exact test, p<0.05). In addition, the OABSS items correlated positively with the corresponding bladder diary variables (Spearman's rho 0.504-0.879) and the degrees of agreement improved with study visits except for nighttime frequency. The Chinese OABSS tended to underestimate the frequency of nighttime voiding.

CONCLUSION

The Chinese OABSS has been developed and validated as a reliable instrument for assessing OAB symptoms. OABSS can be an alternative to, but not a replacement for, a 3-day bladder diary for assessing patients.

Glycine transporter type 2 (GlyT2) inhibitor ameliorates bladder overactivity and nociceptive behavior in rats

BACKGROUND

Glycine is a major inhibitory neurotransmitter in the spinal cord, the concentration of which is regulated by two types of glycine transporters (GlyTs): GlyT1 and GlyT2. We hypothesized that the inhibition of GlyTs could ameliorate bladder overactivity and/or pain sensation in the lower urinary tract.

OBJECTIVE

Investigate the effects of GlyT inhibitors on bladder overactivity and pain behavior in rats.

DESIGN, SETTING, AND PARTICIPANTS

Cystometry was performed under urethane anesthesia in cyclophosphamide (CYP)-treated rats. In behavioral studies using conscious rats, nociceptive responses were induced by intravesical administration of resiniferatoxin (3μM). Selective GlyT1 or GlyT2 inhibitors were administered intrathecally to evaluate their effects.

MEASUREMENTS

Cystometric parameters, nociceptive behaviors (licking and freezing), and messenger RNA (mRNA) levels of GlyTs and glycine receptor (GlyR) subunits in the dorsal spinal cord (L6-S1) were measured.

RESULTS AND LIMITATIONS

During cystometry in CYP-treated rats, significant increases in intercontraction interval and micturition pressure threshold were elicited by ALX-1393, a selective GlyT2 inhibitor, but not by sarcosine, a GlyT1 inhibitor. These effects were completely reversed by strychnine, a GlyR antagonist. ALX-1393 also significantly suppressed nociceptive behaviors in a dose-dependent manner. In sham rats, GlyT2 mRNA was expressed at a much higher level (23-fold) in the dorsal spinal cord than GlyT1 mRNA. In CYP-treated rats, mRNA levels of GlyT2 and the GlyR α1 and β subunits were significantly reduced.

CONCLUSIONS

These results indicate that GlyT2 plays a major role in the clearance of extracellular glycine in the spinal cord and that GlyT2 inhibition leads to amelioration of CYP-induced bladder overactivity and pain behavior. GlyT2 may be a novel therapeutic target for the treatment of overactive bladder and/or bladder hypersensitive disorders such as bladder pain syndrome/interstitial cystitis.

Sensory neurone-specific receptor-mediated regulation of micturition reflex in urethane-anaesthetized rats

OBJECTIVE

•  To investigate the effect of sensory neurone-specific receptors (SNSRs) activation on the micturition reflex in rats.

MATERIALS AND METHODS

•  Continuous cystometrograms (CMGs, 0.04 mL/min) were performed in female Sprague-Dawley rats under urethane anaesthesia. •  After stable micturition cycles were established, a selective rat SNSR1 agonist, bovine adrenal medulla 8-22 (BAM8-22), was administered intravenously (i.v.) or intrathecally (i.t.) in normal rats or rats pretreated with capsaicin 4 days before the experiments. •  Micturition variables were recorded and compared before and after drug administration.

RESULTS

•  Administration (i.v.) of BAM8-22 (3-100 µg/kg) significantly increased intercontraction intervals in a dose-dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. •  Administration (i.t.) of BAM8-22 (0.01-0.3 µg) also increased intercontraction intervals in a dose-dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. •  These inhibitory effects of i.v. (30 µg/kg) or i.t. (0.3 µg) administration of BAM8-22 still occurred after capsaicin pretreatment.

CONCLUSIONS

•  These results indicate that in urethane-anaesthetized rats activation of SNSRs can inhibit the micturition reflex via pathways independent of capsaicin-sensitive C-fibres. •  Thus SNSRs could be a potential target for the treatment of bladder dysfunction, e.g. overactive bladder.

TRPA1 receptor modulation attenuates bladder overactivity induced by spinal cord injury

The ankyrin-repeat transient receptor potential 1 (TRPA1) has been implicated in pathological conditions of the bladder, but its role in overactive bladder (OAB) following spinal cord injury (SCI) remains unknown. In this study, using a rat SCI model, we assessed the relevance of TRPA1 in OAB induced by SCI. SCI resulted in tissue damage, inflammation, and changes in bladder contractility and in voiding behavior. Moreover, SCI caused upregulation of TRPA1 protein and mRNA levels, in bladder and in dorsal root ganglion (DRG; L6-S1), but not in corresponding segment of spinal cord. Alteration in bladder contractility following SCI was evidenced by enhancement in cinnamaldehyde-, capsaicin-, or carbachol-induced bladder contraction as well as in its spontaneous phasic activity. Of relevance to voiding behavior, SCI induced increase in the number of nonvoiding contractions (NVCs), an important parameter associated with the OAB etiology, besides alterations in other urodynamic parameters. HC-030031 (TRPA1 antagonist) treatment decreased the number and the amplitude of NVCs while the TRPA1 antisense oligodeoxynucleotide (AS-ODN) treatment normalized the spontaneous phasic activity, decreased the cinnamaldehyde-induced bladder contraction and the number of NVCs in SCI rats. In addition, the cinnamaldehyde-induced bladder contraction was reduced by exposure of the bladder preparations to HC-030031. The efficacy of TRPA1 AS-ODN treatment was confirmed by means of the reduction of TRPA1 expression in the DRG, in the corresponding segment of the spinal cord and in the bladder, specifically in detrusor muscle. The present data show that the TRPA1 activation and upregulation seem to exert an important role in OAB following SCI.

The supraspinal neural correlate of bladder cold sensation--an fMRI study

In recent years, functional imaging studies have revealed a supraspinal network, which is involved in perception and processing of bladder distention. Very little information exists on the cortical representation of C-fiber transmitted temperature sensation of the human bladder, although C-fibers seem to be involved in the pathomechanisms of bladder dysfunctions. Our aim was, therefore, to evaluate the outcome of bladder cold stimulation on supraspinal activity using functional magnetic resonance imaging (fMRI). A block design fMRI study was performed in 14 healthy females at the MR-center of the University of Zurich. After catheterization, all subjects were investigated in a 3.0-Tesla Scanner. The scanning consisted of 10 repetitive cycles. Each cycle consisted of five conditions: REST, INFUSION, SENSATION, DRAIN 1, and DRAIN 2. Cold saline was passively infused at 4-8°C during scanning. Not more than 100 ml were infused per cycle. Blood-oxygen-level-dependent (BOLD) signal analysis of the different conditions was compared to REST. All activations were evaluated on a random effects level at P = 0.001. Activation of brain regions for bladder cold stimulation (DRAIN 1 period) was found bilaterally in the inferior parietal lobe [Brodmann area (BA) 40], the right insula (BA 13), the right cerebellar posterior lobe, the right middle temporal gyrus (BA 20), and the right postcentral gyrus (BA 3). In conclusion, bladder cooling caused a different supraspinal activation pattern compared to what is known to occur during bladder distention. This supports our hypothesis that cold sensation is processed differently from bladder distension at the supraspinal level.

Autonomous nervous system activity in women with detrusor overactivity

Purpose

To identify autonomic dysfunction among patients with urinary incontinence (UI) with or without detrusor overactivity (DO), we measured and compared heart rate variability (HRV) in these groups.

Materials and Methods

We studied HRV in 12 female UI patients with DO (mean age, 57.3±11.0 years) and 53 female UI patients without DO (mean age, 56.8±9.8 years). HRV parameters were measured by SA-3000P®. Heart rates, the time domain index, and the frequency domain index were compared. To compare time domain indexes, we used the standard deviation of the N-N interval (SDNN), the square root of the mean squared differences of successive N-N intervals (RMSSD), and the frequency domain indexes total power (TP), very low frequency (VLF), low frequency (LF), high frequency (HF), and the low-frequency/high-frequency ratio (LF/HF ratio).

Results

RMSSD values were lower in UI patients with DO than in those without DO, but the values of SDNN and HR showed no significant difference. Whereas the values of LF and HF were lower in UI patients with DO than in those without DO, the LF/HF ratio was higher. TP and VLF were not significantly different.

Conclusions

RMSSD, HF, and LF were lower in DO patients than in controls without DO, but the LF/HF ratio was higher. This suggests that both sympathetic and parasympathetic activity is attenuated in DO, but the autonomic imbalance is higher.

The relationship between sleep apnea and overactive bladder

Approximately 4% to 5% of middle-aged men are affected by obstructive sleep apnea (OSA) syndrome, which is known to cause urologic disorders, cardiovascular diseases, and an increased risk of stroke. The correlation between OSA, erectile dysfunction, and nocturia is well known; a recent study demonstrated the association between overactive bladder and urgency incontinence. This article discusses the current literature and therapeutic options, as well as our own experiences and consequences for affected patients.

Basic fibroblast growth factor causes urinary bladder overactivity through gap junction generation in the smooth muscle

Overactive bladder is a highly prevalent clinical condition that is often caused by bladder outlet obstruction (BOO). Increased coupling of bladder smooth muscle cells (BSMC) via gap junctions has been hypothesized as a mechanism for myogenic bladder overactivity in BOO, although little is known about the regulatory system underlying such changes. Here, we report the involvement of basic fibroblast growth factor (bFGF) and connexin 43, a bladder gap junction protein, in bladder overactivity. BOO created by urethral constriction in rats resulted in elevated bFGF and connexin 43 levels in the bladder urothelium and muscle layer, respectively, and muscle strips from these bladders were more sensitive than those from sham-operated controls to a cholinergic agonist. In vitro bFGF treatment increased connexin 43 expression in cultured rat BSMC via the ERK 1/2 pathway. This finding was supported by another in vivo model, where bFGF released from gelatin hydrogels fixed on rat bladder walls caused connexin 43 upregulation and gap junction formation in the muscle layer. Bladder muscle strips in this model showed increased sensitivity to a cholinergic agonist that was blocked by inhibition of gap junction function with alpha-glycyrrhetinic acid. Cystometric analyses of this model showed typical features of detrusor overactivity such as significantly increased micturition frequency and decreased bladder capacity. These findings suggest that bFGF from the urothelium could induce bladder hypersensitivity to acetylcholine via gap junction generation in the smooth muscle, thereby contributing to the myogenic overactivity of obstructed bladders.

Outcome of a randomized, double-blind, placebo controlled trial of botulinum A toxin for refractory overactive bladder

PURPOSE

We determined the effectiveness of cystoscopic administration of botulinum-A toxin compared to placebo for the treatment of urinary incontinence in subjects with idiopathic overactive bladder.

MATERIALS AND METHODS

Subjects were recruited from the Division of Urogynecology at the University of Rochester. Inclusion criteria were overactive bladder refractory to anticholinergic medications, multiple daily incontinence episodes and a 24-hour pad weight of 100 gm or greater. Subjects with low leak point pressures, increased post-void residual volume or neurological etiologies were excluded from study. Subjects were randomized to placebo or to 1 of 2 doses of botulinum-A toxin. The detrusor was injected at 8 to 10 sites above the trigone. Evaluations were performed at baseline, and at 3 and 6 weeks after injection, and included bladder diaries, pad weights, quality of life questionnaires and urodynamic studies.

RESULTS

A total of 22 subjects participated in stage 1 of this 2-stage study. We report on the outcomes of stage 1 of this study. Because stage 2 is still ongoing and investigators remain blind to the doses of botulinum-A toxin, the 2 botulinum-A toxin groups were combined for this report. There were no differences in mean baseline measurements between the 2 groups. Statistically significant improvements in daily incontinence episodes, pads changed per day and quality of life questionnaires were seen in the botulinum-A toxin group with no changes in the placebo group. No change in nocturia, daily voiding frequency, peak flow or detrusor pressure was seen in either group. Of 15 subjects 4 (26%) receiving botulinum-A toxin had a post-void residual volume of 200 cc or greater and 1 subject required intermittent catheterization. Four subjects experienced a urinary tract infection, 2 (13%) in the botulinum-A toxin group and 2 (28%) in the placebo group (not significant).

CONCLUSIONS

Botulinum-A toxin can significantly reduce urge urinary incontinence due to overactive bladder at 6 weeks. However, there is a risk of urinary retention requiring self-catheterization.