Long-term follow-up of intradetrusor botulinum toxin utilisation: A comparison of patients with multiple sclerosis and idiopathic overactive bladder.

[OBJECTIVES] To assess long-term outcomes (up to 10 cycles) of repeated intradetrusor botulinum toxin (BoNT) utilisation in multiple sclerosis (MS) and idiopathic overactive bladder (OAB).

[MATERIALS AND METHODS] This is a retrospective, international, multi-centre, observational cohort study of patients diagnosed with MS and neurogenic OAB and treated with intradetrusor BoNT between January 2005 and January 2020 (just prior to COVID-19 interruption). Dose, efficacy, duration of effect, International Consultation on Incontinence Questionnaire Overactive Bladder (ICIQ-OAB) and International Consultation on Incontinence Questionnaire Urinary Incontinence (ICIQ-UI) measures and complication rates were recorded. Comparisons were made to those with idiopathic OAB.

[RESULTS] Seven hundred and ninety-two patients received intradetrusor BoNT treatment (104 had MS with neurogenic OAB and 688 had idiopathic OAB). Patients with MS were more likely to receive higher doses of BoNT in all cycles. Self-reported efficacy ranged from 85.7 to 100% (MS) and 87.2 to 100% (idiopathic) with MS patients reporting increased efficacy in cycles 1-3 comparatively ( < 0.05). Duration of effect ranged from 4.5 to 9 months with a reduction in the MS cohort between cycles 1 and 10 (median 8 months vs. 5 months,  = 0.0156).

[CONCLUSION] Patients with MS and neurogenic OAB have a good therapeutic effect from intradetrusor BoNT that is sustained over at least 10 cycles with significant reduction in the duration of action with subsequent cycles.