Optimizing the Injection Schema for Higher Doses of OnabotulinumtoxinA (BTX-A) in the Office Setting: A Randomized Prospective Trial for Patients With Neurogenic Lower Urinary Tract Dysfunction and Idiopathic Overactive Bladder

Background: OnabotulinumtoxinA (BTX-A) decreases urge urinary incontinence (UUI) and improves quality of life for patients with idiopathic overactive bladder (IOAB) and neurogenic lower urinary tract dysfunction (NLUTD). Limited research exists optimizing injection techniques for higher doses (200- or 300-units) of BTX-A in the clinic setting. Optimization with less injections could improve satisfaction and willingness to repeat injections while maintaining effectiveness. Methods: This is a prospective, single-blinded, parallel randomized controlled trial of patients undergoing higher doses of BTX-A for treatment of refractory IOAB or NLUTD in the office setting. Patients were randomized to either 5- or 20-injections. The primary outcome was patients' willingness to repeat the procedure. Secondary outcomes included pain, symptomatology, and adverse events (AEs) assessments. Results: For N = 78 participants (N = 39 per arm), no difference was seen in patients' willingness to repeat the procedure between the 5- or 20-injection groups before and after injection (Mean difference = 0.18, p = 0.57) or at 6–8 week follow-up (Mean difference = 0.06, p = 0.83). There was a significant increase in immediate post-procedural pain after 20 (M = 3.39, SD 3.01) compared to five injections (M = 0.57, SD = 2.07) (Mean difference = 2.83, p > 0.00002). N = 55/78 (71%) completed follow-up. N = 16 experienced AEs (N = 8/26 for 5-injections, N = 7/29 for 20-injections). Conclusions: Despite a significant increase in pain for patients with NLUTD and IOAB receiving 20 injections compared to 5, patients in both groups were equally willing to repeat BTX-A injections. There were no significant differences in AEs or secondary outcomes. This suggests decreasing the number of injections from 20 to 5 will improve pain scores when higher doses of BTX-A are used in the office setting with affecting efficacy. Clinical Trial Number: NCT06059066.