Pain Related to Intradetrusor BotulinumtoxinA: A Randomized Clinical Trial

Importance: OnabotulinumtoxinA (BTX-A) is an effective treatment for overactive bladder (OAB), but few studies have been done to evaluate injection techniques.

Objective: The primary objective was to evaluate procedural discomfort between 2 commonly used injection techniques for BTX-A.

Study design: This was a single-blinded, randomized clinical trial of women undergoing injection of 100 U BTX-A for idiopathic OAB. Patients were randomized to 5 mL/5 injection or 10 mL/10 injection groups. Bladder pain was assessed by a validated Numeric Pain Rating Scale. Overactive bladder symptoms were assessed with a standardized questionnaire (Overactive Bladder Questionnaire Short Form). Patient satisfaction, treatment efficacy, and adverse events were assessed at 30 days after procedure.

Results: One hundred eight patients were randomized to 52 in the 5 mL/5 injection arm and 56 in the 10 mL/10 injection arm. Mean procedural pain scores were 3.2 (±2.3) in the 5 mL/5 injection group versus 3.6 (±2.1) in the 10 mL/10 injection group (P = 0.21). No difference was found when categorizing pain scores into ordinal outcomes of low (P = 0.55), medium (P = 0.70), and high (P = 1.0) or a binary outcome of low (P = 0.55) versus medium + high (P = 0.55). Multivariate analyses did not effect statistical significance between the 2 groups for the ordinal outcome (odds ratio = 1.86; 95% confidence interval = 0.77 = 4.52; P = 0.17) or the binary outcome (odds ratio = 1.81; 95% confidence interval = 0.68-4.77; P = 0.28). No difference was observed between overall patient satisfaction, global impression of improvement, Overactive Bladder Questionnaire Short Form scores, or adverse outcomes.

Conclusions: Procedural discomfort related to BTX-A injection for idiopathic OAB was not different between 2 injection protocols. Overall satisfaction was high for both groups, and there was no difference in symptom scores or adverse events.