Clinical and urodynamic benefit of adding antimuscarinics after a loss of efficacy of intradetrusor botulinum toxin in patients with multiple sclerosis.

[PURPOSE] The aim was to assess in real-life practice the effectiveness of adding antimuscarinics drug (AM) when facing a loss of efficacy of intradetrusor botulinum toxin A (IDBTX-A) in patients with multiple sclerosis (PwMS) on overactive bladder symptoms and urodynamic parameters.

[METHODS] All PwMS who had IDBTX-A injections between January 2023 and December 2023 were screened. Patients with a loss of efficacy of IDBTX-A on bladder symptoms and/or detrusor overactivity, and who received AM as an add-on therapy were included. Data collected were urodynamic parameters (bladder capacity, filling volume of first detrusor overactivity (DO), maximal detrusor pressure at DO, area under curve of detrusor pressure (AUUC)), and clinical parameters (persistence of spontaneous voiding, number of self-catheterization, nocturia, persistence of urgency and/or urge incontinence, number of urinary tract infections (UTI)).

[RESULTS] Thirty-four patients were included (mean age 49 ± 8.7; 20 (58%) women). The rate of patients with DO significantly decreased after AM addition (27 (81%) before AM addition vs. 11 (33%) patients after; p < 0.01). Bladder capacity increase from 311 ± 124 ml to 381 ± 70 ml (p < 0.01) was the only other significant change in urodynamics after AM. The only clinical change was a decrease in the number of patients reporting urgency from 23 (67%) to 11 (32%) (p < 0.01).

[CONCLUSION] Adding antimuscarinics to intradetrusor botulinum toxin for treating DO in PwMS reduces the rate of patients with DO, improves bladder capacity and the occurrence of urgencies.