Reduced versus standard intradetrusor OnabotulinumtoxinA injections for treatment of overactive bladder

Intradetrusor onabotulinumtoxinA injection is an effective advanced treatment for overactive bladder. While the effective dosages have been well studied, very little data exist on treatment efficacy using differing injection techniques. The objective of this study was to determine whether the efficacy of a reduced injection technique of 5 injection sites was noninferior to the standard technique of 20 injection sites of intradetrusor onabotulinumtoxinA for treatment of overactive bladder.

In this randomized noninferiority trial, men and women seeking treatment of overactive bladder with intradetrusor onabotulinumtoxinA injections were randomized to receive 100 units administered via either a reduced injection technique of 5 injection sites or a standard injection technique of 20 injection sites. Subjects completed a series of standardized questionnaires at baseline and at 4-12 weeks postprocedure to determine symptom severity and treatment efficacy. The primary outcome was treatment efficacy as determined by Overactive Bladder Questionnaire-Short Form with a noninferiority margin of 15 points. Secondary outcomes were incidence of urinary tract infection and urinary retention requiring catheterization.

Data from 77 subjects were available for analysis with 39 in the control arm (20 injections) and 38 in the study arm (5 injections). There was a significant improvement in both arms from baseline to follow-up in Overactive Bladder Questionnaire-Short Form and International Consultation on Incontinence Questionnaire scores (p < 0.001). Overall treatment success was 68% with no statistically significant difference between arms. A significant difference between arms was found on the Overactive Bladder Questionnaire-Short Form quality of life survey favoring the control arm (confidence interval [CI]: 0.36-20.5, p = 0.04). However, there were no significant differences between arms in the remaining validated questionnaires. The study arm did not demonstrate noninferiority to the control arm. Subjects in the study arm were significantly more likely to express a willingness to undergo the procedure again (odds ratio = 3.8, 95% CI: 1.42-10.67, p = 0.004). Adverse events did not differ between arms.

A reduced injection technique for administration of intradetrusor onabotulinumtoxinA demonstrates similar efficacy to the standard injection technique but did not demonstrate noninferiority. Subjects preferred the reduced injection technique over the standard technique. A reduced injection technique is a safe and effective alternative to the standard technique.