Therapeutic effects of silodosin and urapidil on underactive bladder associated with diabetic cystopathy.

OBJECTIVES: Pharmacological treatment options for underactive bladder (UAB) syndrome are limited. Urapidil is the only alpha1 -adrenoceptor (AR) antagonist that can be used for urinary disorders in women in some countries. However, no studies have directly verified the effects of alpha1 -AR antagonists on the female urethra and UAB-like dysfunctions. We investigated the effects of silodosin (alpha1A -AR antagonist) and urapidil (nonselective alpha1 -AR antagonist) on the voiding function in female rats with diabetes mellitus (DM). METHODS: Changes in intraurethral pressure (IUP) induced by midodrine (alpha1 -AR agonist) and mean blood pressure (MBP) were continuously measured in normal female rats to verify the pharmacological profiles of the drugs. To establish a DM model, rats were administered streptozotocin (STZ; 50 mg/kg, intravenous). Eight weeks after STZ administration, drugs were subcutaneously delivered through an osmotic pump. Four weeks after drug administration, emptied bladder blood flow (BBF), intravesical pressure, and the micturition volume were measured. RESULTS: Both silodosin and urapidil inhibited the midodrine-induced increase in IUP and decreased MBP in a dose-dependent manner. Silodosin had a more substantial effect on the lower urinary tract than on MBP. Twelve weeks after STZ administration, DM rats exhibited UAB-like dysfunction (increased bladder capacity/bladder weight and residual volume and decreased bladder voided efficiency) and decreased BBF. Both drug treatments controlled this dysfunction. CONCLUSIONS: Alpha1 -AR antagonists induced dose-dependent urethral relaxation in female rats. These drugs ameliorated UAB-like dysfunction in STZ-induced DM rats. In addition, alpha1A -AR antagonists such as silodosin, which have limited effects on blood pressure, appear to be useful for treating UAB.

Muscarinic-3-receptor positive allosteric modulator ASP8302 in patients with underactive bladder. A randomized controlled trial.

AIM: The aim of this study is to evaluate safety and efficacy of ASP8302, a novel positive allosteric modulator for the muscarinic M3 receptor (M3-PAM), in patients with underactive bladder (UAB). METHODS: A randomized, double-blind, placebo-controlled multicenter study was performed in adult male/female subjects with UAB, defined as incomplete bladder emptying (postvoid residual volume [PVR] > 100 ml) without significant bladder outlet obstruction and/or overactive bladder. Subjects were randomized (1:1) to receive 4-week oral once-daily administration of 100 mg ASP8302 or matching placebo. Primary endpoint was a change from baseline in PVR measured by catheterization after standardized bladder filling (PVRC2 ). Other endpoints included PVR and bladder voiding efficiency (BVE) measured in various ways, uroflowmetry, bladder diary, and questionnaires. Pressure-flow studies were performed in a subgroup. RESULTS: One hundred and thirty-five patients were randomized (ASP8302 group: 65 patients, placebo group: 70 patients). The median change in PVRC2 was -40.0 ml (ASP8302) versus -35.0 ml (placebo) and the difference between groups was -5.0 ml (p = 0.960). In males, functional and symptomatic outcomes improved, for example, maximum urine flow rate (Qmax ) and detrusor pressure at Qmax (Pdet.Qmax ) increased (mean difference in change ASP8302 vs. placebo: 3.8 ml/s, p = 0.031 and 12.7 cm H2 O, p = 0.034, respectively). Urinary incontinence episodes/24 h decreased in males with preexisting incontinence (mean difference: -0.35; p = 0.028). The incidence of adverse events was similar between study groups (ASP8302: 33.3%, placebo: 31.4%). In the included subjects, both baseline urine flow and bladder voiding pressure was low. Compared with PVR, simultaneous BVE measurements were more consistent between various methods (spontaneous vs. standardized bladder filling, catheterization vs. ultrasound [US]). CONCLUSIONS: ASP8302 was safe and well tolerated in patients with UAB identified by nonurodynamic clinical criteria, but it did not show efficacy in the primary endpoint. However, in males it showed improvement of symptoms and functional parameters. BVE (using US) is a more optimal outcome measure than PVR in UAB.

The inFlow intraurethral valve-pump for women with detrusor underactivity: A summary of peer-reviewed literature.

Context: Detrusor underactivity (DUA) in women can result in urinary retention and the need for chronic bladder drainage management. Without a cure for urinary retention due to DUA, treatment options are focused on effective bladder drainage most often by intermittent or continuous catheter drainage. The inFlow intraurethral valve pump was FDA approved for use in women with this condition in 2014.Methods: Using a literature search, this clinical review sought to explore the epidemiology and commonly used treatment options for women with DUA and critically examine all available studies of the inFlow urinary prosthesis.Results: Due to a lack of effective treatments to improve detrusor function, DUA is generally considered incurable and there are limited treatment options which mostly focus on effective bladder drainage. The inFlow urinary prosthesis is a unique technology which utilizes a nonsurgically inserted urethral device for females to assist with bladder drainage due to DUA. The inFlow urinary prosthesis has been used in Europe and elsewhere for 20 years and is the subject of seven peer-reviewed clinical studies. For those that tolerate the device (about half), the inFlow urinary prosthesis has a low infection rate and side effect profile, is easy to use, and can normalize urination by returning autonomy to patients and thus improve their quality of life.Conclusion: There is no cure for women with DUA. Bladder drainage can be managed by intermittent or continuous catheterization. Appropriately selected women interested in an alternative to catheterization may be offered an on-device trial of the inFlow urinary prosthesis.

The effectiveness of parasympathomimetics for treating underactive bladder: A systematic review and meta-analysis.

AIMS: Biological rationale suggests that parasympathomimetics (cholinergic receptor stimulating agents) could be beneficial for patients with underactive bladder. However, no systematic review with meta-analysis addressing potential benefits or adverse effects exists. The aim of this review was to assess the effectiveness, both benefits and harms, of using parasympathomimetics for the treatment of underactive bladder. METHODS: The protocol was registered in PROSPERO, and searches undertaken in PubMed, Embase, and CENTRAL, including randomized and non-randomized controlled trials of patients with underactive bladder, comparing parasympathomimetic to placebo, no treatment, or other pharmaceuticals. Risk ratios, odds ratios, and mean differences were calculated. RESULTS: Twelve trials with 3024 participants were included. There was a significant difference between parasympathomimetics and comparators (favoring parasympathomimetics) in the number of patients with urinary retention (risk ratio 0.55, 95% confidence interval [CI] 0.3-0.98, p = 0.04, low quality of evidence). There was no difference in mean postvoid volume overall (MD -41.4 ml, 95% CI -92.0 to 9.1, p = 0.11, low quality of evidence). There was a significant difference at up to 1 week post-intervention, favoring parasympathomimetics (MD -77.5 ml, 95% CI -90.9 to -64.1, p < 0.001, low quality of evidence), but no difference at 1 month post-intervention. There was no difference in adverse events (odds ratio 1.19, 95% CI 0.62-2.28, p = 0.6, moderate quality of evidence). CONCLUSIONS: The evidence supporting the use of parasympathomimetics is of low quality, with relatively short follow-up durations. Overall, it is not possible to draw clear evidence-based conclusions from the current literature, presenting the use of parasympathomimetics for treating underactive bladder as a key area that requires future well-controlled clinical trials.

Bacterial colonization of bladder urothelial cells in women with refractory Detrusor Overactivity: the effects of antibiotic therapy.

Bacterial infection may have a pathophysiological role in refractory Detrusor Overactivity (DO). The aim of this study was to observe any impact of antibiotic therapy upon bacterial colonization of urothelial cells, and to determine whether a relationship existed between colonization and symptom severity. Mid-stream urine samples were collected as part of a clinical trial of antibiotics in women with refractory DO. Wright stained urothelial cells were categorized according to the degree of bacterial colonization as; 'clear' (free of bacteria), or as associated with bacteria that were 'adjacent' to the cell or 'intracellular' at low or high density. The average percentages were compared with routine microbiology cultures, over the 26 week trial, and with patient clinical outcome measures of DO severity. In patients receiving placebo, 'high-density intracellular bacteria' significantly increased during urinary tract infection (P = 0.0008). In antibiotic patients, 'clear' cells were more prevalent. Amoxicillin & Clavulanic Acid significantly decreased bacterial colonization within urothelial cells, suggesting that these antibiotics possess the greatest intracellular efficacy. 'High-density intracellular bacteria' positively correlated with symptom severity, measured by leakage on pad test (P = 0.014), leaks per day (P = 0.004), and voids per day (P = 0.005). Thus, by decreasing high density intracellular bacteria, antibiotic treatment may improve the refractory DO condition.

Excitatory effect of acotiamide on rat and human bladder: Implications for underactive bladder treatment.

OBJECTIVE: To evaluate whether approved gastroprokinetic agent, acotiamide exerts a direct excitatory effect on bladder to help explain the reported meaningful reduction of post-void residual urine volume (PVR) in detrusor underactivity (DU) patients after thrice daily oral intake of acotiamide 100 mg for 2 weeks. METHODS: Effect of acotiamide [1-16 µM] was assessed on nerve-mediated contractions evoked by electrical field stimulation (EFS) for 5 s with 5 ms pulse trains of 10 V in longitudinal, mucosa intact rat and human bladder strips to construct frequency response curve (1-32 Hz) and repeat 10 Hz stimulation at 60s interval. Effect of acotiamide 2 µM on spontaneous and carbachol evoked contractions was also assessed. RESULTS: Acotiamide 2 µM significantly enhanced the Atropine and Tetrodotoxin (TTX)-sensitive EFS evoked contractions of rat and human bladder at 8-32 Hz (Two-way ANOVA followed Sidak's multiple comparison; *p < 0.01) and on repeat 10 Hz stimulation (Paired Student's t-test; *p < 0.05), while producing a modest effect on the spontaneous contractions and a negligible effect on the carbachol evoked contractions. CONCLUSIONS: Enhancement of TTX-sensitive evoked contractions of rat and human bladder by acotiamide is consistent with the enhancement of excitatory neuro-effector transmission mainly through prejunctional mechanisms. Findings highlight immense therapeutic potential of antimuscarinics with low M3 receptor affinity like acotiamide in Underactive bladder (UAB)/DU treatment.

EP2 and EP3 receptors as therapeutic targets for underactive bladder/detrusor underactivity due to diabetic cystopathy in a type 1 diabetic rat model.

OBJECTIVES: Diabetic cystopathy (DC) is recognized as one of the major etiologies of underactive bladder (UAB)/detrusor underactivity (DU). Although DC was first reported about three decades ago, there is a distinct lack of effective pharmacological management methods for UAB/DU due to DC with a robust certainty of evidence. In this study, we investigated whether EP2 and EP3 receptors are promising targets of pharmacological management of UAB/DU due to DC. METHODS: We used streptozotocin (STZ)-induced diabetic Sprague-Dawley rats with postvoid residual urine (PVR) greater than 0.1 mL. Sixteen weeks after induction of diabetes, we performed awake single cystometry after oral administration of the vehicle, an α-blocker (tamsulosin [TAM], 0.1 and 0.3 mg/kg), a cholinesterase inhibitor (distigmine [DIS], 0.3 and 1.0 mg/kg), or an EP2/3 dual agonist (ONO-8055, 0.01 and 0.03 mg/kg). We compared cystometric parameters after administration of the vehicle and drugs using a paired t test. P < .05 was considered to be statistically significant. RESULTS: Compared with the vehicle, TAM significantly decreased maximum intravesical pressure during voiding (Pmax), while DIS significantly increased it. However, neither drug significantly affected PVR or the residual urine rate (RUR). On the other hand, ONO-8055 significantly decreased PVR and tended to decrease RUR, although it did not significantly affect Pmax. CONCLUSION: The present study was unable to demonstrate that stimulation of EP2 and EP3 receptors caused major improvements in UAB/DU due to DC. However, this equivocal result could arise from inherent limitations of the STZ-induced diabetic rat as a UAB/DU model.

Efficacy and safety of botulinum toxin a injection into urethral sphincter for underactive bladder.

BACKGROUND: The aim of this retrospective study was to evaluate the clinical efficacy and safety of botulinum toxin type A (BTX-A) injection into the urethral sphincter to treat patients with underactive bladder (UAB). METHODS: From September 2012 to December 2018, 35 patients with UAB who presented with dysuria were treated with BTX-A (Prosigne®, Lanzhou Biological Products, Lanzhou, China). All patients were evaluated using the International Continence Society standard for video-urodynamic examination before and 1 month after treatment. The index includes maximum urinary flow rate, detrusor leak point pressure, and maximum urethral pressure. Post-voiding residual urine volume was measured using ultrasound before, one and 3 months post injection. RESULTS: After 1 month of treatment, the maximum flow rate increased from 2.5 ± 1.1 ml/s to 6.6 ± 1.7 ml/s (P < 0. 05). The maximum urethral pressure decreased from 73.5 ± 5.8 cmH2o to 45.6 ± 4.3cmH2O (P < 0. 05). The detrusor leak point pressure decreased from 69.9 ± 20.7cmH2O to 26.3 ± 7.4cmH2O (P < 0. 01). Post-voiding residual urine decreased from 282.8 ± 134.2 ml to 125.0 ± 92.1 ml (P < 0. 01) but increased to 270.1 ± 129.0 ml 3 months post injection. Of the 35 patients, 57.1% (20/35) relied on clean intermittent catheterization (CIC) before injection, but 75.0% (15/20) of them could partly void 1 month after injection, and 25%(5/20) could void without CIC. Eight patients showed hydronephrosis before treatment; in three of them, hydronephrosis decreased slightly, while it resolved in two. All patients were followed for three to 6 months, and the effect lasted for about two to 3 months. No serious adverse events occurred in any patient. CONCLUSIONS: The results suggest that Prosigne® injection into the urethral sphincter is an effective, safe, and inexpensive way to treat UAB.

Underactive bladder in aging rats is associated with a reduced number of serotonin-expressing cells in the urethra and is improved by serotonin application to the urethra.

The aim of this study was to determine whether aging-related detrusor underactivity (DU) involves a decrease in 5-hydroxytryptamine (5-HT-positive)-expressing urethral cells and whether 5-HT stimulation of urethral sensory fibers improves detrusor function. Cystometries were performed in young (6 months) and aged (18-24 months) female Wistar rats. Aged rats with voiding contractions (VC) that were 2SD below the mean of those in young rats were considered to have DU. Bladder voiding efficiency (BVE) was calculated during saline or 5-HT solution cystometries. Rats were perfusion-fixed with a fixative solution (paraformaldehyde, PFA 4%) through the circulatory system and the urethra sectioned to count the number of 5-HT-immunoreactive (IR) cells. Isovolumetric cystometry was performed while irrigating the urethra with saline or 5µM-HT solution. Two-tailed unpaired t tests were used to determine the significance of differences. In aged DU rats, the mean (±SD) VC frequency was 0.24 ± 0.07 per minute, with an amplitude of 15 ± 3 cm H2 O. The mean (±SD) number of 5-HT-IR cells in the urethra of aged DU and young rats was 90 ± 11 and 182 ± 25, respectively (P < 0.01). 5-HT improved the mean (±SD) BVE of aged DU rats from 49 ± 3% to 78 ± 2% (P < 0.001). In isovolumetric cystometries, detrusor pressure during irrigation of the urethra with saline was 18 ± 1 cm H2 O, compared with 39 ± 2 cm H2 O during irrigation with 5-HT solution (P < 0.05). In rats, DU associated with aging is accompanied by a decrease in the number of 5-HT-positive cells. The results suggest that decreased 5-HT availability decreases urethral sensory fiber excitation, leading to a decrease the number of effective VC.

Seguridad y eficacia a largo plazo del tratamiento combinado con mirabegrón y solifenacina en comparación con la monoterapia en pacientes con vejiga hiperactiva: estudio SYNERGY II / Long-term safety and efficacy of mirabegron and solifenacin in combination compared with monotherapy in patients with overactive bladder: SYNERGY II study

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Videourodynamic factors predictive of successful onabotulinumtoxinA urethral sphincter injection for neurogenic or non-neurogenic detrusor underactivity.

OBJECTIVE: The aim of the present study was to analyze treatment outcomes and identify videourodynamic factors predictive of successful urethral onabotulinumtoxinA treatment of neurogenic and non-neurogenic detrusor underactivity (DU). METHODS: Patients with DU refractory to medical treatment were treated with injections totaling 100 U onabotulinumtoxinA into the urethral sphincter. Treatment outcomes were assessed 1 month after treatment using the Global Response Assessment. The videourodynamic parameters evaluated included bladder neck status during voiding, bladder sensation, detrusor pressure, maximum flow rate, and post-void residual volume. Treatment outcome was analyzed by patient and baseline videourodynamic characteristics. RESULTS: In all, 60 patients (27 with non-neurogenic and 33 with neurogenic DU) were included in the study and received urethral sphincter injections of 100 U onabotulinumtoxinA in total. Good outcomes were reported in 36 (60%) patients (20 [74.1%] with non-neurogenic and 16 [48.5%] with neurogenic DU). Treatment outcome was significantly better in patients with non-neurogenic than neurogenic DU (P = .039). However, good treatment outcome was not related to age, gender, or any videourodynamic variables, except for an open bladder neck during voiding vs non-opening bladder neck (94.3% vs. 12.0%; P < .0001). The duration of the therapeutic effect was similar between patients with non-neurogenic and neurogenic DU (mean [± SD] 7.37 ± 3.69 vs. 7.69 ± 3.18 months, respectively; P = .788). In all, 12 patients reported de novo urinary incontinence after urethral onabotulinumtoxinA injection, 4 of whom developed stress urinary incontinence and 8 who had exacerbated urgency urinary incontinence. CONCLUSION: Urethral sphincter injection of onabotulinumtoxinA is effective in 60% of patients with DU. Careful videourodynamic interpretation of bladder neck opening enables urologists to select appropriate candidates for onabotulinumtoxinA treatment.

Effect of TRPV4 activation in a rat model of detrusor underactivity induced by bilateral pelvic nerve crush injury.

AIMS: To produce an animal model of peripheral neurogenic detrusor underactivity (DU) and to evaluate the effect of TRPV4 receptor activation in this DU model. METHODS: In female Sprague-Dawley rats, bilateral pelvic nerve crush (PNC) was performed by using sharp forceps. After 10 days, awake cystometrograms (CMG) were recorded in sham and PNC rats. A TRPV4 agonist (GSK 1016790A) with or without a TRPV4 antagonist (RN1734) were administered intravesically and CMG parameters were compared before and after drug administration in each group. The TRPV4 transcript level in the bladder mucosa and histological changes were also evaluated. RESULTS: In CMG, PNC rats showed significant increases in intercontraction intervals (ICI), number of non-voiding contractions (NVCs), baseline pressure, threshold pressure, bladder capacity, voided volumes, and post-void residual (PVR) compared to sham rats. Contraction amplitude and voiding efficiency were significantly decreased in PNC rats. In PNC rats, intravesical application of GSK1016790A (1.5 µM) significantly decreased ICI, bladder capacity, voided volume, and PVR without increasing NVCs, and these effects were blocked by RN1734 (5.0 µM). In contrast, 1.5 µM GSK1016790A had no significant effects on CMG parameters in normal rats. TRPV4 expression within the bladder mucosa of PNC rats was increased in association with urothelial thickening. CONCLUSIONS: Rats with bilateral PNC showed characteristics of DU, and this model seems appropriate for further evaluation of peripheral neurogenic mechanisms of DU. Also, TRPV4 receptors, the activation of which reduced bladder capacity and PVR, could be a target for DU treatment.

Detrusor Underactivity and the Underactive Bladder: A Systematic Review of Preclinical and Clinical Studies.

CONTEXT: Detrusor underactivity (DUA) is a common but relatively under-researched bladder dysfunction. Underactive bladder (UAB) is the symptom-based correlate of DUA. Recently, there has been renewed interest in this topic. OBJECTIVE: To systematically review and summarise the most recent literature and discuss this in the context of what is already known. EVIDENCE ACQUISITION: A systematic review of the literature was performed in December 2017 using Medline and Scopus databases. Separate searches of each database used a complex search strategy including "free text" protocols. Search terms included "underactive bladder", "detrusor underactivity", "acontractile bladder", "detrusor failure", "detrusor areflexia", "atonic bladder", "chronic retention", and "impaired bladder contractility". EVIDENCE SYNTHESIS: The initial search retrieved a total of 1690 studies; of these 44 were included in the final analyses. CONCLUSIONS: Although there has been an expansion in the literature concerning all aspects of DUA and UAB, knowledge on its epidemiology and aetiopathogenesis is still lacking; there remains a need to develop accurate reproducible diagnostic criteria and effective treatments, in particular drug therapies. PATIENT SUMMARY: Recently, there has been renewed interest in underactive bladder with expanding research in this area. The lack of simple, reproducible, noninvasive diagnostic criteria has precluded an accurate estimation of the magnitude of the problem. Recent studies have highlighted the potential role of impaired bladder blood supply in causing bladder underactivity.

Intravesical Activation of the Cation Channel TRPV4 Improves Bladder Function in a Rat Model for Detrusor Underactivity.

BACKGROUND: Improvement of bladder emptying by modulating afferent nerve activity is an attractive therapeutic strategy for detrusor underactivity. Transient receptor potential vanilloid 4 (TRPV4) is a sensory ion channel in urothelial cells that contribute to the detection of bladder filling. OBJECTIVE: To investigate the potential benefit of intravesical TRPV4 agonists in a pelvic nerve injury rat model for detrusor underactivity. DESIGN, SETTING, AND PARTICIPANTS: Female wild-type and Trpv4 knockout rats underwent sham surgery or bilateral pelvic nerve injury (bPNI). Four weeks later, rats underwent cystometry with infusion of the TRPV4 agonist GSK1016790A. Bladders were harvested for in vitro pharmacological studies, quantitative reverse polymerase chain reaction and immunohistochemistry. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Data are expressed as median ± interquartile range. Statistical comparisons were made using the Mann-Witney U test and Wilcoxon signed rank test as appropriate. RESULTS AND LIMITATIONS: Rats with bPNI showed a phenotype characteristic of detrusor underactivity with lower-amplitude voiding contractions, decreased voiding frequency, and increased postvoid residual. Intravesical application of GSK1016790A increased voiding frequency and reduced postvoid residual in wild-type, but not Trpv4-/-, rats. In isolated bladder strips, GSK1016790A did not induce relevant contractions, indicating that the observed improvements in bladder function are the result of increased afferent signalling through TRPV4 activation, rather than a local effect on the detrusor. The altered urinary phenotype of Trpv4-/- mice was not apparent in the Trpv4-/- rat model, suggesting species-related functional variations. Our results are limited to the preclinical setting in rodents. CONCLUSIONS: Intravesical activation of TRPV4 improves bladder dysfunction after bPNI by increasing afferent signalling. PATIENT SUMMARY: We demonstrate that the sensory protein transient receptor potential vanilloid 4 (TRPV4) can be targeted to improve bladder function in animals that have iatrogenic injury to the nerves innervating the bladder. Further research is required to determine whether these results can be translated to patients with an underactive bladder.

Are There Pharmacotherapeutic Options for Underactive Bladder?

Currently, underactive bladder, the symptom-based correlate of the urodynamic diagnosis of detrusor underactivity, has no effective drug treatments. Use of sympathomimetics, targeting cholinergic receptors, is not supported by current evidence. Several potential targets are the subject of ongoing investigation.

New therapeutic directions to treat underactive bladder.

Underactive bladder (UAB) is a term used to describe a constellation of symptoms that is perceived by patients suggesting bladder hypocontractility. Urodynamic measurement that suggest decreased contractility of the bladder is termed detrusor underactivity (DUA). Regulatory approved specific management options with clinically proven ability to increase bladder contractility do not currently exist. While DUA specific treatments presumably will focus on methods to increase efficiency of bladder emptying capability relying on augmenting the motor pathway in the micturition reflex, other approaches include methods to augment the sensory (afferent) contribution to the micturition reflex which could result in increased detrusor contractility. Another method to induce more efficient bladder emptying could be to induce relaxation of the bladder outlet. Using cellular regenerative techniques, the detrusor smooth muscle can be targeted so the result is to increase detrusor smooth muscle function. In this review, we will cover areas of potential new therapies for DUA including: drug therapy, stem cells and regenerative therapies, neuromodulation, and urethral flow assist device. Paralleling development of new therapies, there also needs to be clinical studies performed that address how DUA relates to UAB.