Efficacy and Safety of Combination Pharmacotherapy for Patients with Overactive Bladder: A Rapid Evidence Assessment

Treatment modalities for paediatric functional daytime lower urinary tract disorders: an updated review

Paediatric functional bladder disorders especially those causing daytime symptoms are a common cause of significant psychosocial and/or physical morbidity and impaired quality of life. Despite the availability of many therapeutic modalities, a significant number of children appear to be refractory to treatment and continue to have symptoms. In this review, we aim to evaluate the current evidence in the use of existing and novel therapeutic options for the management of daytime lower urinary tract disorders in children. We also aim to highlight the controversies around the terminology and diagnosis of paediatric lower urinary tract dysfunction (LUTD) and specific conditions. The article will then provide a reasonable critique of the existing and emerging treatment modalities in functional daytime LUTD in children including their mode of action, efficacy, indications, and recent advances. These include standard urotherapy, specific urotherapy comprised of biofeedback, alarm therapy and electrical neural stimulation and pharmacotherapy involving selective and non-selective anticholinergics, ß3 adrenergic agonists, alpha blockers and botulinum toxin. A better understanding of this common clinical problem may help clinicians achieve better profiling of these children's diagnoses to further enable specific, targeted treatment.

Current optimal pharmacologic therapies for overactive bladder

INTRODUCTION

Overactive bladder (OAB) is a common syndrome in adults. Current pharmacologic treatment includes antimuscarinic agents and β-3 adrenoceptor agonists. For non-responders to oral medication, intravesical injection of botulinum toxin A (BoNT-A) is an effective option. However, these treatments have potential adverse events and should be cautiously selected for appropriate patients. This review presents the recently published results of clinical trials and studies for patients with OAB and the underlying pathophysiology of OAB. Appropriate medical therapy based on pathophysiology of OAB is also presented.

AREAS COVERED

Literature search from Pubmed from 2001 to 2023 including clinical background, pharmacology, and clinical studies for OAB medications.

EXPERT OPINION

Treatment of OAB syndrome with any antimuscarinic or β-3 adrenoceptor agonist is feasible as a first-line approach. For patients with suboptimal therapeutic effect to full-dose antimuscarinics or mirabegron, combination with both drugs can improve efficacy. Intravesical BoNT-A 100-U injection provides therapeutic effects for refractory OAB. Patients who are refractory to initial pharmacotherapies should be investigated for the underlying pathophysiology; then an appropriate medication can be added, such as an α1-blocker or anti-inflammatory agents. Patient education about behavioral modification and therapies should always be provided with oral medication or BoNT-A injection for OAB patients.

Possible involvement of brain hydrogen sulphide in the inhibition of the rat micturition reflex induced by activation of brain alpha7 nicotinic acetylcholine receptors

We previously reported that brain α7 nicotinic acetylcholine receptors inhibited the rat micturition reflex. To elucidate the mechanisms underlying this inhibition, we focused on the relationship between α7 nicotinic acetylcholine receptors and hydrogen sulphide (H₂S) because we found that H₂S also inhibits the rat micturition reflex in the brain. Therefore, we investigated whether H₂S is involved in the inhibition of the micturition reflex induced by the activation of α7 nicotinic acetylcholine receptors in the brain. Cystometry was performed in male Wistar rats under urethane anesthesia (0.8 g/kg, ip) to examine the effects of icv pre-treated GYY4137 (H₂S donor, 1 or 3 nmol/rat) or aminooxyacetic acid (AOAA; non-selective H₂S synthesis inhibitor, 3 or 10 μg/rat) on PHA568487 (α7 nicotinic acetylcholine receptor agonist, icv)-induced prolongation of intercontraction intervals. PHA568487 administration at a lower dose (0.3 nmol/rat, icv) had no significant effect on intercontraction intervals, while under pre-treatment with GYY4137 (3 nmol/rat icv), PHA568487 (0.3 nmol/rat, icv) significantly prolonged intercontraction intervals. PHA568487 at a higher dose (1 nmol/rat, icv) induced intercontraction interval prolongation, and the PHA568487-induced prolongation was significantly suppressed by AOAA (10 μg/rat, icv). The AOAA-induced suppression of the PHA568487-induced intercontraction interval prolongation was negated by supplementing H₂S via GYY4137 at a lower dose (1 nmol/rat, icv) in the brain. GYY4137 or AOAA alone showed no significant effect on intercontraction intervals at each dose used in this study. These findings suggest a possible involvement of brain H₂S in inhibiting the rat micturition reflex induced by activation of brain alpha7 nicotinic acetylcholine receptors.

Mirabegron is better tolerated than solifenacin in Sjogren's syndrome patients with overactive bladder symptoms-A randomized controlled trial

OBJECTIVES

This study investigates the efficacy and adverse events of beta-3 agonists and antimuscarinic agents for managing overactive bladder syndrome in Sjogren syndrome.

METHODS

Sjogren's syndrome patients with an Overactive Bladder Symptom Score (OABSS) >5 were enrolled and were randomly assigned to mirabegron 50 mg/day or solifenacin 5 mg/day. Patients were evaluated on the recruitment day and reassessed at Week 1, 2, 4, and 12. The study's primary endpoint was to have a significant change in OABSS at Week 12. The secondary endpoint was the adverse event and crossover rate.

RESULTS

A total of 41 patients were included in the final analysis, with 24 in the mirabegron group and 17 in the solifenacin group. The study's primary outcome was a change of the OABSS at Week 12. We found that both mirabegron and solifenacin significantly reduce patients' OABSS after 12 weeks of treatment. The evolution of the OABSS was -3.08 for mirabegron and -3.71 for solifenacin (p = .56). Six out of 17 patients from the solifenacin group crossed over to the mirabegron arm due to severe dry mouth or constipation, while none from the mirabegron arm crossed over to the solifenacin group. Sjogren's syndrome-related pain was also improved in the mirabegron group (4.96-1.67, p = .008) compared to the solifenacin group (4.39-3.4, p = .49).

CONCLUSIONS

Our study showed that mirabegron is equally effective as solifenacin in treating Sjogren's syndrome patients with overactive bladder. Mirabegron is superior to solifenacin in terms of treatment-related adverse events.

Comparison of different types of therapy for overactive bladder: A systematic review and network meta-analysis

To compare the efficacy and safety of different interventions [including antimuscarinics, mirabegron, OnabotulinumtoxinA, sacral neuromodulation (SNM) and peripheral tibial nerve stimulation (PTNS)] for treating idiopathic overactive bladder (OAB). PubMed, Embase, Cochrane Library, and other sources were searched for randomized controlled trials (RCTs) comparing interventions for overactive bladder from 1 January 2000 to 19 April 2021. A systematic review and network meta-analysis were performed by two authors independently. Fifty-five RCTs involving 32,507 patients were included in this analysis. Overall, antimuscarinics, mirabegron, OnabotulinumtoxinA, sacral neuromodulation, and peripheral tibial nerve stimulation were more efficacious than placebo, and sacral neuromodulation showed the best effect for reducing micturition frequency, urgency episodes and urgency urinary incontinence episodes. OnabotulinumtoxinA was the best intervention for achieving reductions of 100 and ≥50% in the number of urinary incontinence episodes/day, and peripheral tibial nerve stimulation was the best intervention for reducing urinary incontinence episodes. Antimuscarinics, mirabegron and peripheral tibial nerve stimulation had a similar efficacy for reducing micturition frequency, urinary incontinence episodes and urgency urinary incontinence episodes. The results revealed that all interventions examined herein were efficacious for managing adult overactive bladder syndrome compared with placebo. Furthermore, sacral neuromodulation and OnabotulinumtoxinA were the most efficient treatments for overactive bladder.

Combination and Novel Pharmacologic Agents for OAB

PURPOSE OF REVIEW

To evaluate recent literature on combination and novel pharmacologic therapies for overactive bladder (OAB).

RECENT FINDINGS

Combination therapies demonstrating greater efficacy than monotherapy include combination anticholinergics, anticholinergic plus β-3 agonist, and anticholinergic with behavioral modification, percutaneous tibial nerve stimulation, or sacral neuromodulation. Promising novel therapies include new bladder selective anticholinergics, new β-3 agonists, and gabapentin. OAB is a symptom complex caused by dysfunction in the interconnected neural, muscular, and urothelial systems that control micturition. Although several therapeutic targets and treatment options exist, complete resolution is not always achieved, discontinuation rate for medical therapy is high, and few patients subsequently progress to third-line treatment options. Recent literature suggests combination therapy diversifying therapeutic targets is more effective than targeting a single pathway and novel treatments targeting additional pathways have promising results.

Utilization rate and long-term persistence of combination pharmacotherapy with β3-agonists and antimuscarinics for overactive bladder refractory to monotherapy in a real-world setting

AIM

To assess real-world treatment profiles, including utilization rate, time to and reasons for discontinuation of combination pharmacotherapy with β₃ -agonists and antimuscarinics for refractory overactive bladder (OAB) through a retrospective chart review.

METHODS

We retrospectively reviewed the records of OAB patients who received β₃ -agonists or antimuscarinics at our hospital between 2012 and 2020 and analyzed the clinical course of patients who progressed to combination therapy. Data on age, sex, major complaints, OAB symptom score at the initiation of combination therapy, treatment persistence, and reasons for discontinuation were collected. Treatment persistence was assessed with respect to the median time to discontinuation and persistence rate at 12 months.

RESULTS

Of the 2163 patients receiving β₃ -agonists or antimuscarinics, only 84 (3.8%) progressed to combination therapy with both drug classes. At therapy initiation, most (98%) of these patients had moderate to severe OAB symptoms. Median treatment duration and 12-month persistence rate for combination therapy were 595 days and 64.0%, respectively. The reasons for discontinuation were insufficient treatment efficacy followed by adverse effects including voiding impairment in nearly 10% of the patients. None of the baseline parameters was independently associated with persistence in the multivariate analysis.

CONCLUSION

While underutilized among OAB patients refractory to monotherapy, combination pharmacotherapy showed a greater persistence rate than published mirabegron or antimuscarinic monotherapy when applied to patients with moderate to severe symptoms. Treatment-emergent voiding impairment is a concern associated with this mode of therapy. A small sample size at a single institution is the limitation of this study.

Stimulation of brain corticotropin-releasing factor receptor type1 facilitates the rat micturition via brain glutamatergic receptors

Corticotropin-releasing factor (CRF), a representative stress-related neuropeptide, in the central nervous system reportedly both facilitates and suppresses the micturition, therefore, roles of central CRF in regulation of the micturition are still controversial. In this study, we investigated (1) effects of intracerebroventricularly (icv)-administered CRF on the micturition, and (2) brain CRF receptor subtypes (CRFR1/CRFR2) and glutamatergic receptors (NMDA/AMPA subtypes) involved in the CRF-induced effects in male Wistar rats under urethane anesthesia. Intercontraction intervals (ICI), and maximal voiding pressure (MVP), were evaluated by continuous cystometry 45 min before CRF administration or intracerebroventricular pretreatment with other drugs as follows and 3 h after CRF administration. Single-voided volume (Vv), post-voiding residual volume (Rv), bladder capacity (BC), and voiding efficiency (VE) were evaluated by single cystometry 60 min before CRF administration and 60-120 min after the administration. Icv-administered CRF reduced ICI, Vv, and BC without changing MVP, Rv, or VE. The CRF-induced ICI reduction was attenuated by icv-pretreated CP154526 (CRFR1 antagonist), MK-801 (NMDA receptor antagonist), and DNQX (AMPA receptor antagonist), but not by K41498 (CRFR2 antagonist). These results indicate that stimulation of brain CRFR1 can be involved in facilitation of the rat micturition via brain NMDA/AMPA receptors.

Comparison of antimuscarinic drugs to beta adrenergic agonists in overactive bladder: A literary review

BACKGROUND

The purpose of this study was to carry an extended literature review to compare antimuscarnics with beta adrenergic agonists (mirabegron) in treatment of overactive bladder.

MATERIALS AND METHODS

A literature review was carried out, using key words in different databases including MEDLINE, PUBMED, and EMBASE. All relevant published articles during last 5 years with full texts available were included in this review for critical analysis and evaluation. In total, there were 20 studies including 7 systemic reviews, 6 retrospective cohort, 3 prospective cohort, 2 randomized controlled trials, and 2 cross sectional studies.

RESULTS

After critical evaluation the results were considered under parameters of efficacy, adverse effects, adherence and persistence, tolerability, cost-effectiveness. In 9 studies efficacy was evaluated, 5 studies dealt with adverse effects, same number evaluated adherence and persistence. Cost effectiveness was compared in 3 and same number of studies also compared tolerability.

CONCLUSIONS

To conclude, we found mirabegron is as efficacious as any other antimuscarnics, has better tolerability (including elderly), has better adverse effect profile, is cost effective, has better persistence and adherence rates at 12 months.

Management of Lower Urinary Tract Symptoms after Prostate Radiation

PURPOSE OF REVIEW

To present urologists with guidance on how to approach and manage lower urinary tract symptoms (LUTS) in patients who have undergone radiation therapy (RT) for prostate cancer.

RECENT FINDINGS

There are few studies that specifically examine treatment approaches for LUTS in patients who have undergone prostate cancer RT. LUTS after prostate RT are unique when compared to de novo LUTS. Understanding these distinctions is important for urologists' practice as well as patients' quality of life. Discussion of the risks and management of post-RT LUTS should be included in the shared decision-making process when counseling patients on various treatment options for prostate cancer. Further studies evaluating treatments for storage and voiding symptoms after RT are needed to help guide future care.

Solifenacin/Mirabegron Induces an Acute Compliance Increase in the Filling Phase of the Capacity-Reduced Urinary Bladder: A Pressure-Volume Analysis in Rats

Aims: Pressure in the bladder, which is a high compliance organ, is only slightly elevated to a considerable filling volume during storage. Although cystometry off-line offers mean compliance, no protocol is available for real-time assays of the dynamics of bladder compliance, and the potential impact of solifenacin and mirabegron on dynamic bladder compliance has not been established.

Methods: Along with constantly infused cystometry, a pressure-volume analysis (PVA) was performed by plotting intra-vesical volume against pressure in Sprague-Dawley rats. The instant compliance was assayed as the slope of the trajectory, and the mean compliance (Cm) was determined by the slope of the line produced by regression of the data points at the end of the first, second, and third quarters of the filling phase.

Results: Under a steady-state, the PVA trajectory moved clockwise which shaped coincident enclosed loops with stable compliance. Though administering to naïve animals solifenacin, but not mirabegron (both 1 × 10⁻⁵−1 × 10⁻¹ mg/kg, i.a.) decreased the peak pressure, both of these reagents exhibited acute increments in the trajectory slope and Cm of the filling phase in a dose-dependent manner (ED₅₀ = 1.4 × 10⁻⁴ and 2.2 × 10⁻⁵ mg/kg, respectively). Resembling urine frequency/urgency in OAB patients, the voiding frequency of a capacity-reduced bladder was increased in association with decreased compliance which was ameliorated by both acute solifenacin and mirabegron injections (both 1 × 10−1 mg/kg).

Conclusion: In addition to their well-known anti-inotropic/relaxative effects, solifenacin, and mirabegron induce an acute increase in bladder compliance to ameliorate OAB-like syndromes. Together with time-domain cystometry, PVA offers a platform for investigating the physiology/pathophysiology/pharmacology of bladder compliance which is crucial for urine storage.

Stimulation of brain α7-nicotinic acetylcholine receptors suppresses the rat micturition through brain GABAergic receptors

Brain nicotinic acetylcholine receptors (nAChRs) reportedly suppress the micturition, but the mechanisms responsible for this suppression remain unclear. We previously reported that intracerebroventricularly administered (±)-epibatidine (non-selective nAChR agonist) activated the sympatho-adrenomedullary system, which can affect the micturition. Therefore, we investigated (1) whether intracerebroventricularly administered (±)-epibatidine-induced effects on the micturition were dependent on the sympatho-adrenomedullary system, and (2) brain nAChR subtypes involved in the (±)-epibatidine-induced effects in urethane-anesthetized male Wistar rats. Plasma noradrenaline and adrenaline (catecholamines) were measured just before and 5 min after (±)-epibatidine administration. Evaluation of urodynamic parameters, intercontraction intervals (ICI) and maximal voiding pressure (MVP) by cystometry was started 1 h before (±)-epibatidine administration or intracerebroventricular pretreatment with other drugs and continued 1 h after (±)-epibatidine administration. Intracerebroventricularly administered (±)-epibatidine elevated plasma catecholamines and prolonged ICI without affecting MVP, and these changes were suppressed by intracerebroventricularly pretreated mecamylamine (non-selective nAChR antagonist). Acute bilateral adrenalectomy abolished the (±)-epibatidine-induced elevation of plasma catecholamines, but had no effect on the (±)-epibatidine-induced ICI prolongation. The latter was suppressed by intracerebroventricularly pretreated methyllycaconitine (selective α7-nAChR antagonist), SR95531 (GABAA antagonist), and SCH50911 (GABAB antagonist), but not by dihydro-β-erythroidine (selective α4β2-nAChR antagonist). Intracerebroventricularly administered PHA568487 (selective α7-nAChR agonist) prolonged ICI without affecting MVP, similar to (±)-epibatidine. These results suggest that stimulation of brain α7-nAChRs suppresses the rat micturition through brain GABAA/GABAB receptors, independently of the sympatho-adrenomedullary outflow modulation.

Systematic review and meta-analysis of the efficacy and safety of vibegron vs antimuscarinic monotherapy for overactive bladder

BACKGROUND

Vibegron is a new β3-adrenergic receptor agonist which has been demonstrated for the treatment of overactive bladder (OAB). We carried out meta-analysis to evaluate the efficiency of vibegron vs antimuscarinic monotherapy for treating OAB.

METHODS

Randomized controlled trials (RCTs) of Vibegron vs antimuscarinic monotherapy for OAB were searched systematically by using EMBASE, MEDLINE, and the Cochrane Controlled Trials Register. The RevMan version 5.3.0. was used to analysis the data.

RESULTS

Three RCTs involving a total of 1751 patients were studied in the Systematic review and Meta-analysis. Efficacy end points: the mean number of micturitions episodes/d (P = .16); the mean number of urgency episodes/d (P = .05); mean number of urgency incontinence episodes/d (P = .11) and mean number of incontinence episodes/d (P = .14) indicated that vibegron and antimuscarinic had no significant differences in terms of OAB treatment. Mean volume voided/micturition showed a distinct difference in the two groups (P = .009). With regard to dry mouth and drug related treatment-emergent adverse event (TEAE), vibegron showed better tolerance than antimuscarinic. Serious adverse event (SAE) and discontinuations due to adverse event (AE) did not show a significant difference between the two groups.

CONCLUSIONS

The therapeutic effect of vibegron is similar to that of antimuscarinic, but vibegron does not increase the risk of AE.

Current management of refractory overactive bladder

Overactive bladder (OAB) is a common condition affecting one-sixth to one-fifth of the global population. The treatment of refractory OAB remains a challenge for urologists. Current treatment options include the use of combination therapy with antimuscarinic agents and beta-3 adrenoceptor agonists, and treating underlying curable disorders. Intravesical botulinum toxin type A (BoNT-A) injection, percutaneous tibial nerve stimulation, and sacral nerve stimulation are third-line management therapies suggested by the American Urological Association/Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction (AUA/SUFU) guidelines. In rare cases, more invasive surgical interventions can be considered after explaining the benefits and risks to the patients. Augmentation cystoplasty has a high success rate; however, it has also been associated with a high complication rate. In contrast, detrusor myomectomy is an easy procedure, but the treatment outcome remains controversial. Liposome-encapsulated BoNT-A is administered via bladder instillation, and promising results have been obtained in preliminary studies. More therapies are currently being investigated, and transient receptor potential vanilloid 1 antagonists may be new type of medication. Radiofrequency ablation and other targets for neuromodulation have also been studied; however, more evidence is needed to confirm their efficacy.

Update on non-invasive treatment for female overactive bladder

Overactive bladder syndrome (OAB) is common chronic medical condition which has a major impact on health and quality of life. This condition affects daily activities, performance and social function and servers as a real challenge for care giver in attempt to treat patients' symptoms. Given the fact that therapy rarely results in cure and the high rate of discontinuation, treatment should primarily aim to reduce social and psychological disability. The purpose of our update is to give an overview of recent data regarding OAB, and to provide practical clinical tools for evaluation and management of OAB syndrome according to current literature evidence.