Outcomes of Intravesical Onabotulinumtoxina Between Patients With Interstitial Cystitis/Painful Bladder Syndrome Versus Overactive Bladder

INTRODUCTION: Interstitial cystitis/bladder pain syndrome (IC/BPS) and overactive bladder (OAB) are highly prevalent pelvic floor conditions, with detrimental effects on health and quality of life. Intravesical OnabotulinumtoxinA (BoNT-A) is an option when conservative measures and medications fail to improve symptoms for OAB and IC/BPS. Although OAB and IC/BPS patients have overlapping symptoms, the treatment success and adverse events may differ between these groups; specific comparisons of these are unknown. OBJECTIVE: The primary objective is to compare BoNT-A treatment success after first injection in patients with OAB without IC/PBS versus those with IC/PBS (with or without OAB). Secondary objectives include comparing rates of adverse events (urinary tract infections or UTI, urinary retention, systemic Botox effect, or other major adverse event) within 30 days after first injection, rates of adverse events after any injection, dosing difference, and treatment interval between the two groups. METHODS: This study is a retrospective study of adults treated at a single tertiary-care academic institution from January 2015 to June 2023 with BoNT-A treatment for OAB or IC/PBS. Those with neurogenic bladder, self-catheterization at baseline, no follow-up within 3 months of procedure, or who had concomitant procedures in the operating room were excluded. Eligible patients were identified by CPT code for BoNT-A in the urogynecology and urology clinics and operating rooms. Success was dichotomized, defined as patient-reported success based on symptom improvement as documented in the medical record and no new retreatment within 3 months of BoNT-A. UTI was defined as culture-proven, treated UTI and urinary retention was defined as PVR >200 cc with symptoms or >300 cc. Categorical/binary variables were compared between groups using Fisher’s exact test and Wilcoxon-Mann-Whitney test performed for ordinal or linear data. RESULTS: 186 patients met inclusion criteria, n=144 in the OAB-only group and n=32 in the IC/PBS group. Sociodemographic and clinical data were similar between groups (Table 1) except for age, with the IC/PBS group being younger (median age 56 in IC/PBS vs 63 in OAB, p<0.001). Success was similar between groups: 25/32 (78.1%) in the IC/PBS group vs 115/144 (79.9%) in the OAB group (p=0.811). There was no significant difference in rate of any adverse event (AE) after first injection between groups: 9/32 (28.1%) IC/PBS vs 14/144 (13.9%) OAB, p=0.065. After first injection, UTI rates were 2/32 (6%) IC/PBS vs 14/144 (10%) OAB, p=0.74, and urinary retention rates were 4/32 (12.5%) IC/PBS vs 9/144 (6%) OAB, p=0.26. There was no significant difference in rate of any AE following any of the series of injections: 11/32 (34.4%) IC/PBS vs 36/144 (25.0%) OAB, p=0.278. CONCLUSIONS: In this retrospective analysis, treatment success of BoNT-A was similar between patients with OAB and with IC/PBS. Overall number of adverse events was low; however, the rate of urinary retention was approximately double in the IC/PBS group as compared to the OAB group. Further research is necessary to study BoNT-A in this population.