Pain Related to Intradetrusor BotulinumtoxinA: A Randomized Clinical Trial

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

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

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.

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.

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.