Current Status of Intravesical Therapies for Bladder Pain Syndrome (BPS): A Narrative Review of Emerging Evidence

Bladder instillations vs onabotulinumtoxinA injection for interstitial cystitis/bladder pain syndrome: a randomized clinical trial

BACKGROUND

Interstitial cystitis (IC)/bladder pain syndrome (BPS) is an unpleasant sensation related to the bladder with lower urinary tract symptoms lasting more than 6 weeks, unrelated to an otherwise identifiable cause. The etiology is likely multifactorial including urothelial abnormalities, neurogenic pain upregulation, and potentially bladder and vaginal microbiome alterations. Despite treatment effectiveness of both bladder instillations and intradetrusor onabotulinumtoxinA injection for this condition, a head-to-head comparison has not been performed.

OBJECTIVE

To compare the efficacy of bladder instillations and intradetrusor onabotulinumtoxinA injection for treatment of IC/BPS.

STUDY DESIGN

Patients with O'Leary-Sant (OLS) questionnaire scores of ≥6, meeting clinical criteria for IC/BPS, and desiring procedural management were randomized to bladder instillations or intradetrusor onabotulinumtoxinA injection. The primary outcome was the difference in OLS scores at 2 months posttreatment between groups. Secondary outcomes included evaluation of sexual function, physical/mental health status, pain, patient satisfaction, treatment perception, retreatment, and adverse event rates.

RESULTS

Forty-seven patients were analyzed with 22 randomized to bladder instillations and 25 to onabotulinumtoxinA injection. There were no differences in demographic and clinical characteristics between groups. From baseline to 2 months posttreatment, there was a decrease in OLS subscales in all patients (Interstitial Cystitis Symptom Index [ICSI] -6.3 (confidence interval [CI] -8.54, -3.95), P<.0001; Interstitial Cystitis Problem Index [ICPI] -5.9 (CI -8.18, -3.57), P<.0001). At 2 months posttreatment, patients in the onabotulinumtoxinA group had significantly lower OLS scores compared to those in the bladder instillation group (ICSI 6.3±4.5 [onabotulinumtoxinA] vs 9.6±4.2 [instillation], P=.008; ICPI 5.9±5.1 [onabotulinumtoxinA] vs 8.3±4.0 [instillation], P=.048). The difference in OLS scores between groups did not persist at 6 to 9 months posttreatment. There were no statistically significant differences between baseline and posttreatment time points for the remaining questionnaires. Eight percent of patients who received onabotulinumtoxinA injection experienced urinary retention requiring self-catheterization. Patients who underwent onabotulinumtoxinA injection were significantly less likely to receive retreatment within 6 to 9 months compared to patients who received bladder instillations (relative risk 13.6; 95% CI, 1.92-96.6; P=.0002). There were no differences between groups regarding patient satisfaction, perception of treatment convenience, or willingness to undergo retreatment.

CONCLUSION

Both onabotulinumtoxinA injection and bladder instillations are safe, effective treatments for patients with IC/BPS, with significant clinical improvement demonstrated at 2 months posttreatment. Our findings suggest that intradetrusor onabotulinumtoxinA injection is a more effective procedural treatment for this condition than bladder instillation therapy and associated with decreased rates of retreatment.

Interstitial Cystitis Chatter: A Qualitative Evaluation of Bladder Instillation Online

OBJECTIVE

To qualitatively assess the perception and experiences of bladder instillation for interstitial cystitis among women on Reddit, a widely used anonymous social media platform.

METHODS

"r/interstitialcystitis," a Subreddit with >27,000 subscribers, was queried for bladder instillation among women with interstitial cystitis in November 2023. Posts were analyzed qualitatively by 3 independent researchers. Grounded theory principles were applied to derive preliminary themes. These themes were then used to develop emergent themes.

RESULTS

Sixty-three posts with 637 responses published between 2022-2023 were analyzed. Qualitative analysis yielded 4 themes: (1) IC/BPS anxiety and depression, (2) limited treatment options for IC/BPS pain, (3) exhausting all IC/BPS treatment options before bladder instillation, (4) bladder instillation ineffectiveness for IC/BPS pain. Three emergent concepts were derived: (1) a prevailing sense of desperation for relief among women with IC/BPS, (2) women are fearful and apprehensive about bladder instillation, (3) a perception of bladder instillation as the final recourse for women suffering from IC/BPS.

CONCLUSION

This study represents the first evaluation of bladder instillation as a therapeutic from a social media community focused exclusively on IC/BPS. These results capture patient's experiences with nonurological associated syndromes and indicate a role for physicians to address mental health concerns in patients with IC/BPS, in addition to opportunities to improve patient education on bladder instillations.

Characterization and Therapeutic Potential of Curcumin-Loaded Cerium Oxide Nanoparticles for Interstitial Cystitis Management

Oxidative stress resulting from reactive oxygen species (ROS) is often considered to be the leading cause of interstitial cystitis (IC), which is a chronic inflammatory disease. Antioxidants have been proven to have promising therapeutic effects on IC. In this study, we present an antioxidant intervention for IC by introducing curcumin-loaded cerium oxide nanoparticles (Cur-CONPs). Recognizing oxidative stress as the primary contributor to IC, our research builds on previous work utilizing cerium oxide nanoparticles (CONPs) for their outstanding antioxidant and anti-inflammatory properties. However, given the need to effectively relieve acute inflammation, we engineered Cur-CONPs to harness the short-term radical-scavenging antioxidant prowess of curcumin. Through in vitro studies, we demonstrate that the Cur-CONPs exhibit not only robust antioxidant capabilities but also superior anti-inflammatory properties over CONPs alone. Furthermore, in vivo studies validate the therapeutic effects of Cur-CONPs on IC. Mice with IC subjected to the Cur-CONP treatment exhibited improved micturition behaviors, relief from pelvic pain sensitivity, and reduced expression of inflammatory proteins (IL-6, IL-1β, TNF-α, Cox2). These findings suggest that the synergistic antioxidant properties of the Cur-CONPs that combine the sustained antioxidant properties of CONPs and acute anti-inflammatory capabilities of curcumin hold promise as a novel treatment strategy for IC.

Progress and challenges in intravesical drug delivery

INTRODUCTION

Intravesical drug delivery (IDD) has gained recognition as a viable approach for treating bladder-related diseases over the years. However, it comes with its set of challenges, including voiding difficulties and limitations in mucosal and epithelial penetration. These challenges lead to drug dilution and clearance, resulting in poor efficacy. Various strategies for drug delivery have been devised to overcome these issues, all aimed at optimizing drug delivery. Nevertheless, there has been minimal translation to clinical settings.

AREAS COVERED

This review provides a detailed description of IDD, including its history, advantages, and challenges. It also explores the physical barriers encountered in IDD, such as voiding, mucosal penetration, and epithelial penetration, and discusses current strategies for overcoming these challenges. Additionally, it offers a comprehensive roadmap for advancing IDD into clinical trials.

EXPERT OPINION

Physical bladder barriers and limitations of conventional treatments result in unsatisfactory efficacy against bladder diseases. Nevertheless, substantial recent efforts in this field have led to significant progress in overcoming these challenges and have raised important attributes for an optimal IDD system. However, there is still a lack of well-defined steps in the workflow to optimize the IDD system for clinical settings, and further research is required to establish more comprehensive in vitro and in vivo models to expedite clinical translation.

Bladder instillation patterns in a cohort of women with interstitial cystitis/bladder pain syndrome

Purpose

To determine intravesical instillation patterns among women receiving treatment for interstitial cystitis/bladder pain syndrome (IC/BPS).

Methods

Using the Veterans Affairs Informatics and Computing Infrastructure, active female users of the Veterans Affairs system with an ICD-9 diagnosis of IC/BPS (595.1) were randomly sampled. Patients were considered to have IC/BPS (by chart review) if they had two visits complaining of bladder-centric pain in the absence of positive urine culture ≥6 weeks apart or history of bladder pain with one additional visit for bladder-centric pain. We abstracted the dates of intravesical instillations for each patient. A "course" of instillations was defined as ≥1 instillations made with <21 days between visits.

Results

We identified 641 women with confirmed diagnosis of IC/BPS, 78 of whom underwent a total of 344 intravesical instillations. On average each subject had 1.5 +/- 0.8 courses between October 2004-July 2016. Each course was an average of 3.1 +/- 2.6 instillations. 55% of courses consisted of one instillation. Only 22% of courses had 6 or more instillations, the number typically recommended to achieve clinical response. Each instillation within a course was an average of 9.4 +/- 4.0 days apart. Most instillations (77%) were a cocktail of two or more drugs.

Conclusions

In our cohort, few women with IC/BPS received a recommended treatment course of six weekly instillations, with most receiving only one per course. Future studies are needed to determine if instillation courses were altered from the guideline due to provider practice patterns, early improvement, or poor tolerance of instillations.

Recurrence after postoperative intravesical instillation therapy in Hunner type interstitial cystitis

We performed a prospective, single-arm study comparing outcomes between transurethral ablation plus postoperative instillation of hyaluronic acid and chondroitin sulfate (HACS group) and transurethral ablation only in patients with Hunner type interstitial cystitis (historical control group). A total of 78 patients were enrolled, and 51 were included in the per-protocol analysis set. The 2-year recurrence rate was 47.1% (95% CI, 32.9-61.5) in the HACS group, which was significantly lower than that in the control group (86.2%; 95% CI, 74.6-93.9, P < 0.001). After instillation therapy, the hazard ratio for recurrence was 0.38 (95% CI, 0.23-0.65, P < 0.001). The HACS group had an increased recurrence-free survival with the median interval not being reached, while it was 11.4 months in the control group (95% CI, 8.8-13.8, P < 0.001). Regardless of the instillation treatment, there were significant improvements in all symptom questionnaire scores and pain compared to the baseline. However, in the instillation group, improvement was stable even after 12 months. In patients with Hunner type interstitial cystitis, intravesical instillation of hyaluronic acid and chondroitin sulfate after transurethral ablation significantly reduced the recurrence rate and maintained symptom improvement for more than 1 year.

Current status of patient-reported outcome measures and other subjective assessment grading tools in bladder pain syndrome

INTRODUCTION AND HYPOTHESIS

Bladder pain syndrome (BPS) is characterised by chronic pain in the bladder area accompanied by urgency and/or frequency without the presence of other confusable diseases. Owing to a lack of gold standard diagnostic tests and definitive cure it is paramount to define treatment goals and validated measurements of outcomes. Patient-reported outcome measures (PROMs) are validated questionnaires completed by patients that can help to reduce ambiguity in the BPS patient treatment pathway, but they are currently underutilised. We present to our knowledge the first summary and analysis of all available PROMs in BPS patients.

METHODS

Review and critical evaluation of all relevant BPS guidelines presented in English language and a systematic search for PubMed database articles relating to PROMs and subjective assessment grading tools in BPS, interstitial cystitis and chronic pelvic pain syndrome.

RESULTS

The ideal PROMs for BPS should assess urinary symptoms, pain, quality of life and sexual health. There are five PROMs designed specifically for BPS patients. The most universally used and quoted is the O'Leary-Sant questionnaire followed by the Pelvic Pain and Urgency Score and the Wisconsin Interstitial Cystitis scale. However, there is no single PROM for BPS that is ideal, and for comprehensive assessment several questionnaires are often used simultaneously.

CONCLUSIONS

Patient-reported outcome measures are a valuable tool for use in the long-term management of patients burdened with BPS. There are now several disease-specific PROMs in use that have their respective advantages and disadvantages. Their use should be encouraged in future research as well as continued efforts to develop new PROMs that can address current shortcomings.

Management of Bladder Pain Syndrome (BPS): A Practical Guide

Bladder pain syndrome (BPS) is a prevalent and pervasive disease. The physical and psychological sequelae can be very burdensome for the patient, and the condition represents a real challenge for the clinician as well. With no simple pathognomonic test, finding harmony in navigating patient care can be demanding. Diagnosis and management rely upon a multidisciplinary and holistic approach. Treatment options include conservative measures and pharmacotherapies as well as bladder instillation therapies. Ultimately, surgery may be offered but only in cases of refractory disease. This article offers a pragmatic guide for clinicians managing this challenging disease.