# Intravesical Botulinum Toxin Type A for an Overactive Bladder: A Single-Center Audit

## TL;DR

This study evaluates the effectiveness and safety of botulinum toxin injections for treating overactive bladder in a real-world patient group.

## Contribution

The study provides real-world clinical outcomes of BoNT-A therapy in a diverse patient population with refractory overactive bladder.

## Key findings

- 82.4% of patients experienced treatment success with botulinum toxin type A injections.
- Neurogenic detrusor overactivity patients were more likely to require post-treatment catheterization.
- The median effect duration of the treatment was six months.

## Abstract

Background

Intravesical administration of botulinum toxin type A (BoNT-A) is an established third-line intervention for patients with refractory overactive bladder (OAB). With BoNT-A therapy now widely adopted, ongoing audits remain important to capture real-world outcomes across different patient groups. This retrospective audit assessed the clinical outcomes of BoNT-A therapy in a heterogeneous patient population treated at a university-affiliated teaching hospital.

Methodology

We conducted a retrospective audit of 193 patients who received intravesical BoNT-A injections for OAB between January and December 2024. Patients underwent urodynamic testing to confirm diagnosis, and all cases were discussed in multidisciplinary team meetings where approval was given for BoNT-A treatment. Demographic data, treatment parameters, efficacy outcomes, adverse events, and catheterization requirements were systematically analyzed. Statistical analyses included chi-square tests and Fisher’s exact tests to evaluate associations between variables.

Results

The cohort included 164 (85%) females and 29 (15%) males, with a median age of 62 years. The primary indications for BoNT-A therapy were idiopathic detrusor overactivity (IDO, n = 149, 77.2%), neurogenic detrusor overactivity (NDO, n = 41, 21.2%), and sensory urgency (n = 3, 1.6%). Treatment success was observed in 82.4% (n = 159) of patients, with partial improvement in 4.1% (n = 8) and treatment failure in 11.9% (n = 23). The overall urinary tract infection (UTI) rate was 4.7% (n = 9), with diabetic patients exhibiting a three-fold increased risk (11.5% vs. 3.6%), but this did not reach statistical significance (χ² = 3.195, df = 1, p = 0.074; Fisher’s p = 0.105). Post-treatment catheterization was required in 29.5% (n = 57) of cases, predominantly among patients with NDO (n = 22, 53.7% vs. IDO, n=37, 25%). First-time BoNT-A administration occurred in 21.7% (n = 42) of patients, while the majority (n = 151, 78.3%) received repeat injections during the study period, with a mean of seven treatment cycles. The median duration of effect following intravesical BoNT‑A was six months (interquartile range = 5). The mean duration was 6.7 ± 4.0 months.

Conclusions

Intravesical BoNT-A demonstrates robust efficacy and an acceptable safety profile in the management of refractory OAB, with sustained therapeutic benefits necessitating repeat administration. Diabetic status may predispose patients to an increased risk of post-procedural UTIs, while those with NDO are more likely to require catheterization. These findings support BoNT-A as a valuable therapeutic option in the stepwise management of OAB, particularly when combined with appropriate patient selection and counseling.