The Efficacy and Safety between Intradetrusor OnabotulinumtoxinA Injection and Combined Pharmacotherapy in Patients with Refractory Overactive Bladder: A Randomized Controlled Trial.

Abstract

PURPOSE To investigate whether intradetrusor onabotulinumtoxinA injection demonstrates superior efficacy and fewer side effects compared to combined pharmacotherapy in patients with refractory overactive bladder. MATERIAL AND METHODS In this single-center, open-label, randomized trial, patients with urodynamically confirmed detrusor overactivity and persistent symptoms despite at least two months of single pharmacotherapy were randomized to receive onabotulinumtoxinA injection (100 U) or combined pharmacotherapy with solifenacin 5 mg and mirabegron 25 mg. Assessments at baseline and 12 weeks included voiding parameters, adverse events, and patient-reported outcomes using the Urogenital Distress Inventory, the Incontinence Impact Questionnaire, and the Overactive Bladder Symptom Score. RESULTS Of 74 patients enrolled, 66 completed the study (33 per group). Both treatments reduced urgency episodes to a median of 2.0 per 24 hours at 12 weeks. The mean difference between groups was -0.1 (95% CI: -1.5 to 1.4; p = 0.925), indicating no significant difference. Improvements in urinary frequency, nocturia, urge incontinence, and quality-of-life measures were observed in both groups, without significant differences. However, adverse effects such as dry mouth, constipation, and blurred vision were significantly more common with pharmacotherapy (all p < 0.05). CONCLUSION Both intradetrusor onabotulinumtoxinA and combined pharmacotherapy improved symptoms in women with refractory overactive bladder. OnabotulinumtoxinA demonstrated a more favorable safety profile and represents an appropriate option for patients sensitive to systemic anticholinergic effects or preferring non-daily interventions.