Video-urodynamic effects of vibegron, a new selective β3-adrenoceptor agonist, on antimuscarinic-resistant neurogenic bladder dysfunction in patients with spina bifida

Bladder Compliance: How We Define It and Why It Is Important

Bladder compliance is the relationship between detrusor pressure and bladder storage volume. We discuss the definition of compliance, how it may be accurately measured, and its clinical relevance. Specifically, we discuss the association between low compliance and upper urinary tract deterioration. We discuss medical and surgical therapies that have been demonstrated to improve compliance and reduce upper tract risk. Finally, we propose a model, which not only considers compliance but also differential pressure between the bladder and ureters, and how this may also be an accurate predictor of upper tract deterioration. We call for further investigation to test this model.

[EFFECTS OF COMBINATION THERAPY WITH VIBEGRON FOR ANTICHOLINERGIC-RESISTANT PEDIATRIC NEUROGENIC BLADDER]

(Objective) We report the effectiveness of combination therapy with vibegron in pediatric patients with neurogenic bladder inadequately responding to anticholinergic agents. (Subjects and methods) This retrospective study involved 13 pediatric patients with neurogenic bladder treated with anticholinergics at our department from November 2019 to January 2021 who had an inadequate response and received combination therapy with vibegron. Changes in the volume of urinary incontinence before and after the use of vibegron reported during interviews from the 13 patients were compared. In addition, bladder capacity at the end of examination, bladder capacity at the end of examination/expected bladder capacity (EBC), and bladder compliance were compared using the Wilcoxon signed rank test in 9 patients for whom urodynamics (UDS) or video urodynamics (VUDS) was performed before and after introduction of vibegron. (Results) The 13 patients comprised 8 boys and 5 girls. The median age was 13 years (range, 5-18 years). Underlying diseases included 9 cases of spina bifida, 1 case of Hinman syndrome, 1 case of cervical vertebra injury, 1 case of idiopathic cervical epidural hematoma combined with spina bifida, and 1 case of spinal cord infarction. Eight of the 13 patients experienced decrease in urinary incontinence after the introduction of vibegron. All 9 patients who underwent UDS or VUDS before and after introduction of vibegron displayed significant differences in bladder capacity at the end of the examination, bladder capacity at the end of the examination/EBC, and bladder compliance, indicating improvement. (Conclusion) Combination therapy with vibegron is effective for pediatric patients with neurogenic bladder who have inadequately responded to anticholinergic agents.

Bladder Management Strategies for Urological Complications in Patients with Chronic Spinal Cord Injury

Neurogenic lower urinary tract dysfunction, common in patients with chronic spinal cord injury, inevitably results in urological complications. To address neurogenic lower urinary tract dysfunction after spinal cord injury, proper and adequate bladder management is important in spinal cord injury rehabilitation, with the goal and priorities of the protection of upper urinary tract function, maintaining continence, preserving lower urinary tract function, improvement of SCI patients' quality of life, achieving compatibility with patients' lifestyles, and decreasing urological complications. This concise review aims to help urologists address neurogenic lower urinary tract dysfunction by focusing on the risks of long-term urological complications and the effects of different bladder management strategies on these complications based on scientifically supported knowledge.

Urodynamic evaluation of the efficacy of vibegron, a new β3-adrenergic receptor agonist, on lower urinary tract function in children and adolescents with overactive bladder

INTRODUCTION

Idiopathic overactive bladder (OAB) is defined as an urgency symptom with or without urge incontinence, which is not due to known neurological abnormalities. Since children present with variable symptoms, pediatric nonneurogenic idiopathic OAB is a condition that is difficult to diagnose and treat. Although there are few reports on bladder function in pediatric patients compared to adult patients, it can be useful for diagnosis. Antimuscarinic therapy is the pharmacological mainstay of OAB management. However, antimuscarinic use is limited by side effects and Insufficient effects. Vibegron, a new drug with a different mechanism of action (β3-adrenoreceptor agonist), was recently introduced for treating OAB in adults but has not been studied in the pediatric population.

OBJECTIVE

This study aimed to determine the efficacy and tolerability of vibegron in children and adolescents with idiopathic OAB.

STUDY DESIGN

We conducted a retrospective study enrolling pediatric patients with OAB whose symptoms did not improve with behavioral therapy or pharmaceutical therapy. Efficacy and tolerability were assessed via a question, and patients underwent video-urodynamic testing before and during treatment with once-daily 50 mg vibegron. Statistical differences were evaluated using Wilcoxon matched-pairs signed-rank tests.

RESULTS

Out of the 17 patients that were recruited, full study with two urodynamic studies were confirmed by 11 patients. OAB symptoms improved in 14 (82.4%) patients, and 3 patients discontinued treatment because of ineffectiveness. No patients discontinued treatment because of intolerance to vibegron. The median (IQR) first desire to void (133 [82-185]-161 [123-227] mL), bladder capacity (158 [136-238]-204 [150-257] mL), and bladder compliance (18.1 [9.1-76.7]-34.0 [30.0-82.3] mL/cm H₂O) improved significantly post treatment compared to before treatment. Detrusor overactivity disappeared in one of the eight patients with this condition. The parameters of voiding function did not change significantly after the administration of vibegron.

DISCUSSION

Treatment with vibegron significantly improved clinical and urodynamic parameters of pediatric OAB with no adverse effects. Little information is available regarding the feasibility of switching drugs when patients discontinue prior pharmacological therapy because of insufficient efficacy or poor tolerability in children. Vibegron may be a promising OAB treatment option with a better balance of efficacy and tolerability.

CONCLUSIONS

Vibegron is an alternative agent for pediatric patients with idiopathic OAB for improving both subjective symptoms and lower urinary tract function. Future prospective randomized studies with larger sample sizes must be conducted to validate the results of the present study.

Vibegron for the treatment of overactive bladder: a comprehensive update

INTRODUCTION

: Overactive bladder (OAB) is associated with physical, emotional and financial burden. After failed conservative measures, second-line therapy includes medications, such as antimuscarinics and beta-3 adrenergic receptor (β3AR) agonists. Antimuscarinics are most commonly prescribed but have systemic side effects that lead to poor compliance. β3AR agonists include mirabegron and vibegron. Mirabegron is a first generation β3AR agonist that has shown to be effective for frequency, urgency urinary incontinence (UUI) and urgency, but has interactions with cytochrome P450 enzymes (CYPs) and cardiovascular sequelae. Vibegron is a second generation β3AR agonist that is highly selective and does not interact with CYPs. It has shown to be very effective for reducing UUI episodes and daily micturition number and has a favorable side effect profile.

AREAS COVERED

: Clinical background, pharmacology, and clinical studies for vibegron.Expert opinion: Vibegron is a welcomed addition to the OAB therapeutic landscape. This single dose, once daily option is effective, especially for patients with wet OAB, with a favorable side effect profile. Sub-analyses of patients ≥ 65 years have shown continued efficacy and safety. The few drug interactions are of benefit, especially for older patients with polypharmacy. As long-term data accrues, vibegron has the potential to drive the OAB therapeutic market.

Neurogenic Bladder Physiology, Pathogenesis, and Management after Spinal Cord Injury

Urinary incontinence is common after spinal cord injury (SCI) due to loss of supraspinal coordination and unabated reflexes in both autonomic and somatic nervous systems; if unchecked, these disturbances can become life-threatening. This manuscript will review normal anatomy and physiology of the urinary system and discuss pathophysiology secondary to SCI. This includes a discussion of autonomic dysreflexia, as well as its diagnosis and management. The kidneys and the ureters, representing the upper urinary tract system, can be at risk related to dyssynergy between the urethral sphincters and high pressures that lead to potential vesicoureteral reflux, urinary tract infections, and calculi associated with neurogenic lower urinary tract dysfunction (NLUTD). Recent guidelines for diagnosis, evaluation, treatment and follow up of the neurogenic bladder will be reviewed and options provided for risk stratification and management. Mechanical, pharmacological, neurolysis and surgical management will be discussed.