Pharmacotherapy of overactive bladder: epidemiology and pathophysiology of overactive bladder

Exploring lifelong overactive bladder: Transitions, evidence, and clinical implications; A modified Delphi process

INTRODUCTION

Overactive bladder (OAB) is a prevalent urological condition characterized by urinary urgency, with or without urgency urinary incontinence, accompanied by increased daytime frequency and nocturia. However, the current definition of OAB lacks a specified time frame, hindering our understanding of the temporal aspects and transitions that occur within the OAB spectrum.

METHODS

A modified Delphi study was conducted in three rounds, involving a panel of international experts in functional urology, urogynaecology, geriatrics, transitional medicine, and pediatric urology. The study took place between February 2023 and June 2023 and employed two sequential rounds of online surveys, followed by a final hybrid group discussion session in June 2023.

RESULTS

The Delphi process resulted in a consensus definition of lifelong OAB as a persistent and continuous condition that may manifest differently from birth and evolve over time, with varying levels of clinical perception. The course of its progression is influenced by transition periods and modifying factors, mainly anatomical, hormonal, and psychosocial/stressors. Three main transition periods were identified: achievement of daytime continence, adulthood to elderly, and transition to frail elderly. The panel also considered the therapeutic and diagnostic implications of lifelong OAB, as well as future research prospects in terms of importance and feasibility.

CONCLUSIONS

Future longitudinal research is needed to develop this concept and further identify transitions and temporal dynamics.

Single-interface bioelectronic medicines - concept, clinical applications and preclinical data

Presently, large groups of patients with various diseases are either intolerant, or irresponsive to drug therapies and also intractable by surgery. For several diseases, one option which is available for such patients is the implantable neurostimulation therapy. However, lacking closed-loop control and selective stimulation capabilities, the present neurostimulation therapies are not optimal and are therefore used as only "third" therapeutic options when a disease cannot be treated by drugs or surgery. Addressing those limitations, a next generation class of closed-loop controlled and selective neurostimulators generically named bioelectronic medicines seems within reach. A sub-class of such devices is meant to monitor and treat impaired functions by intercepting, analyzing and modulating neural signals involved in the regulation of such functions using just one neural interface for those purposes. The primary objective of this review is to provide a first broad perspective on this type of single-interface devices for bioelectronic therapies. For this purpose, the concept, clinical applications and preclinical studies for further developments with such devices are here analyzed in a narrative manner.

Closed-loop sacral neuromodulation for bladder function using dorsal root ganglia sensory feedback in an anesthetized feline model

Overactive bladder patients suffer from a frequent, uncontrollable urge to urinate, which can lead to a poor quality of life. We aim to improve open-loop sacral neuromodulation therapy by developing a conditional stimulation paradigm using neural recordings from dorsal root ganglia (DRG) as sensory feedback. Experiments were performed in 5 anesthetized felines. We implemented a Kalman filter-based algorithm to estimate the bladder pressure in real-time using sacral-level DRG neural recordings and initiated sacral root electrical stimulation when the algorithm detected an increase in bladder pressure. Closed-loop neuromodulation was performed during continuous cystometry and compared to bladder fills with continuous and no stimulation. Overall, closed-loop stimulation increased bladder capacity by 13.8% over no stimulation (p < 0.001) and reduced stimulation time versus continuous stimulation by 57.7%. High-confidence bladder single units had a reduced sensitivity during stimulation, with lower linear trendline fits and higher pressure thresholds for firing observed during stimulation trials. This study demonstrates the utility of decoding bladder pressure from neural activity for closed-loop control of sacral neuromodulation. An underlying mechanism for sacral neuromodulation may be a reduction in bladder sensory neuron activity during stimulation. Real-time validation during behavioral studies is necessary prior to clinical translation of closed-loop sacral neuromodulation.

Real-Time Bladder Pressure Estimation for Closed-Loop Control in a Detrusor Overactivity Model

Overactive bladder (OAB) patients suffer from a frequent urge to urinate, which can lead to a poor quality of life. Current neurostimulation therapy uses open-loop electrical stimulation to alleviate symptoms. Continuous stimulation facilitates habituation of neural pathways and consumes battery power. Sensory feedback-based closed-loop stimulation may offer greater clinical benefit by driving bladder relaxation only when bladder contractions are detected, leading to increased bladder capacity. Effective delivery of such sensory feedback, particularly in real-time, is necessary to accomplish this goal. We implemented a Kalman filter-based model to estimate bladder pressure in real-time using unsorted neural recordings from sacral-level dorsal root ganglia, achieving a 0.88 ± 0.16 correlation coefficient fit across 35 normal and simulated OAB bladder fills in five experiments. We also demonstrated closed-loop neuromodulation using the estimated pressure to trigger pudendal nerve stimulation, which increased bladder capacity by 40% in two trials. An offline analysis indicated that unsorted neural signals had a similar stability over time as compared to sorted single units, which would require a higher computational load. We believe this paper demonstrates the utility of decoding bladder pressure from neural activity for closed-loop control; however, real-time validation during behavioral studies is necessary prior to clinical translation.

Use of health care resources and associated costs in non-institutionalized vulnerable elders with overactive bladder treated with antimuscarinic agents in the usual medical practice

OBJECTIVE

To evaluate the use of resources and health costs in vulnerable elderly institutionalized patients with overactive bladder (OAB) treated with fesoterodine, tolterodine or solifenacin in routine medical practice.

MATERIAL AND METHODS

A multicenter retrospective study, from the records of patients treated during 2008-2010 in three geographical locations and starting treatment with antimuscarinic (fesoterodine, solifenacin and tolterodine) for OAB. The attribute of vulnerability was based on collecting at least 3 of the Vulnerable Elders Survey criteria-13, age>75 years, poor/average age for health and difficulty in at least one daily physical activity.

MAIN MEASURES

morbidity, persistence and resource use and costs. Monitoring of patients was conducted over 52 weeks. A general linear model with covariates and bootstraping (1000) at random was used to construct the 95% CI of the cost differences between drugs.

RESULTS

Records of 552 patients (50.8% women, mean age: 80.2 years) were analyzed. Treated with fesoterodine (N=58), solifenacin (N=252) or tolterodine (N=212). The use of absorbent was 20.7%, 29.4% and 33.0% (P=.186), respectively. Persistence to treatment was slightly greater with fesoterodine. The patient healthcare costs/year were lower with fesoterodine, €1,775 (1550-2014) vs. solifenacin €2,062 (1911-2223) and tolterodine €2,149 (1,978-2,307), P=.042, as a result of lower utilization visits and concomitant medication.

CONCLUSIONS

Despite the potential limitations of the study, the vulnerable elderly non institutionalized patients with OAB treated with fesoterodine, compared to solifenacin or tolterodine were associated with lower resource utilization and healthcare costs.

Purinergic signalling in the urinary tract in health and disease

Purinergic signalling is involved in a number of physiological and pathophysiological activities in the lower urinary tract. In the bladder of laboratory animals there is parasympathetic excitatory cotransmission with the purinergic and cholinergic components being approximately equal, acting via P2X1 and muscarinic receptors, respectively. Purinergic mechanosensory transduction occurs where ATP, released from urothelial cells during distension of bladder and ureter, acts on P2X3 and P2X2/3 receptors on suburothelial sensory nerves to initiate the voiding reflex, via low threshold fibres, and nociception, via high threshold fibres. In human bladder the purinergic component of parasympathetic cotransmission is less than 3 %, but in pathological conditions, such as interstitial cystitis, obstructed and neuropathic bladder, the purinergic component is increased to 40 %. Other pathological conditions of the bladder have been shown to involve purinoceptor-mediated activities, including multiple sclerosis, ischaemia, diabetes, cancer and bacterial infections. In the ureter, P2X7 receptors have been implicated in inflammation and fibrosis. Purinergic therapeutic strategies are being explored that hopefully will be developed and bring benefit and relief to many patients with urinary tract disorders.

Health economics perspective of fesoterodine, tolterodine or solifenacin as first-time therapy for overactive bladder syndrome in the primary care setting in Spain

Background

Overactive bladder (OAB) is associated with high healthcare costs, which may be partially driven by drug treatment. There is little comparative data on antimuscarinic drugs with respect to resource use and costs. This study was conducted to address this gap and the growing need for naturalistic studies comparing health economics outcomes in adult patients with OAB syndrome initiating treatment with different antimuscarinic drugs in a primary care setting in Spain.

Methods

Medical records from the databases of primary healthcare centres in three locations in Spain were assessed retrospectively. Men and women ≥18 years of age who initiated treatment with fesoterodine, tolterodine or solifenacin for OAB between 2008 and 2010 were followed for 52 weeks. Healthcare resource utilization and related costs in the Spanish National Health System were compared. Comparisons among drugs were made using multivariate general linear models adjusted for location, age, sex, time since diagnosis, Charlson comorbidity index, and medication possession ratio.

Results

A total of 1,971 medical records of patients (58.3% women; mean age, 70.1 [SD:10.6] years) initiating treatment with fesoterodine (n = 302), solifenacin (n = 952) or tolterodine (n = 717) were examined. Annual mean cost per patient was €1798 (95% CI: €1745; €1848). Adjusted mean (95% bootstrap CI) healthcare costs were significantly lower in patients receiving fesoterodine (€1639 [1542; 1725]) compared with solifenacin (€1780 [€1699; €1854], P = 0.022) or tolterodine (€1893 [€1815; €1969], P = 0.001). Cost differences occurred because of significantly fewer medical visits, and less use of absorbent products and OAB-related concomitant medication in the fesoterodine group.

Conclusions

Compared with solifenacin and tolterodine, fesoterodine was a cost-saving therapy for treatment of OAB in the primary care setting in Spain.

Rates of self-reported urinary, gastrointestinal, and pain comorbidities in women with vulvar lichen sclerosus

OBJECTIVE

The study aimed to determine the prevalences of comorbid disorders in women with vulvar lichen sclerosus.

MATERIALS AND METHODS

A retrospective review of self-administered questionnaires regarding the health history of 308 women with lichen sclerosus seen at a vulvar clinic between 2006 and 2011 was performed. Responses to questions about urinary (overactive bladder [OAB], urinary incontinence [UI], and stress UI), gastrointestinal (inflammatory bowel diseases, constipation, and irritable bowel syndrome), thyroid dysfunction and pain (interstitial cystitis, fibromyalgia, temporomandibular joint disorder, and vulvar pain) disorders were collected. The percentage of subjects self-reporting each comorbidity was compared with the published prevalence in the general population using a single-value binomial test.

RESULTS

Subject demographics (data presented as median [range] or percentage): age, 56.4 years (20.0-92.5); body mass index, 27.5 kg/m2 (17.4-53.1); parity 2 (0-10); white, 92.9%; and biopsy proven 65.6%. Prevalences of self-reported comorbidities in our subjects are as follows: OAB, 15.3%; UI, 38.6%; stress UI, 27.9%; inflammatory bowel diseases, 1.9%; constipation, 32.5%; irritable bowel syndrome, 19.5%; thyroid dysfunction, 33.1%; interstitial cystitis, 2.6%; fibromyalgia, 9.1%; temporomandibular joint disorder, 13.0%; and vulvar pain, 83.1%. The prevalence of each disorder is significantly different from that in the general population, with all p values ≤ .02.

CONCLUSIONS

Vulvar lichen sclerosus is associated with numerous bladder, bowel, and pain comorbidities. The prevalences of all of these disorders are higher in our subjects than the general population except OAB, which we find at approximately one third of the general population. Patients with lichen sclerosus should be screened for comorbidities that may affect their health and/or quality of life.