Oral phenazopyridine vs intravesical lidocaine for bladder onabotulinumtoxinA analgesia: a randomized controlled trial.

Background: The efficacy of intradetrusor onabotulinumtoxinA injections for the management of idiopathic overactive bladder has been well-established. The injections are typically performed in the office setting using local analgesia, most commonly a 20 to 30-minute intravesical instillation of lidocaine. There are limited data evaluating alternative bladder analgesics.

Objective: To compare pain scores with preprocedure oral phenazopyridine vs intravesical lidocaine in women undergoing intradetrusor onabotulinumtoxinA injections for idiopathic overactive bladder.

Study Design: Nonpregnant adult females with idiopathic overactive bladder, scheduled for office injection of 100 units of intradetrusor onabotulinumtoxinA were randomized to either 200 mg of oral phenazopyridine taken 1 to 2 hours preprocedure or a 20-minute preprocedure intravesical instillation of 50 mL of 2% lidocaine. We excluded participants with neurogenic bladders, and those who had received intradetrusor onabotulinumtoxinA injections in the previous 12 months. The primary outcome was pain measured by a 100-mm visual analog scale. Demographic characteristics and overall satisfaction with the procedure were also recorded. Providers answered questions about cystoscopic visualization, ease of procedure, and perception of participant comfort. Prespecified noninferiority margin was set to equal the anticipated minimum clinically important difference of 14 mm. A planned sample of 100 participants, 50 in each treatment arm, provided 80% power to detect noninferiority at a significance level of.05. We performed a modified intention-to-treat analysis and compared variables with the t test or the Fisher exact test.

Results: A total of 111 participants were enrolled, and complete data were obtained for 100 participants; 47 participants were randomized to phenazopyridine and 53 to lidocaine. Baseline characteristics did not differ between groups. There were 19.6% and 20.8% of participants in the phenazopyridine and lidocaine groups, respectively, who previously underwent intradetrusor onabotulinumtoxinA injections. The mean postprocedure pain was 2.7 mm lower in the phenazopyridine group than in the lidocaine group (95% confidence interval, -11.3 to 10.7), demonstrating noninferiority. More than 90% of participants in both groups stated that the pain was tolerable. Slightly more participants reported being "very satisfied" in the lidocaine group, although this was not statistically significant (50.0% vs 40.4%; P=.34). Providers reported clear visualization in 89.4% of participants in the phenazopyridine group and in 100% of participants in the lidocaine group (P=.02). Provider perception of participant comfort and overall ease of procedure were not different between groups. Length of time in the exam room was significantly shorter in the phenazopyridine than in the lidocaine group (44.4 vs 57.5 minutes; P=.0003).

Conclusion: In women receiving intradetrusor onabotulinumtoxinA injections for idiopathic overactive bladder, oral phenazopyridine was noninferior to intravesical lidocaine for procedural pain control. Phenazopyridine is well-tolerated by participants, allows for the procedure to be performed with similar ease, and is associated with shorter appointment times.