Scarce evidence on the role of the antimuscarinic drug Solifenacin (Sol) for the treatment of Neurogenic Overactive Bladder syndrome (nOAB) in patients affected by Multiple Sclerosis (MS) exists. nOAB is defined by ICS as: Urinary urgency, usually accompanied by increased daytime frequency and/or nocturia, with urinary incontinence (OAB-wet) or without (OAB-dry), in the absence of urinary tract infection or other detectable disease in the setting of a clinically relevant neurologic disease.
The aim of this study is to analyse the efficacy and tolerability of Sol in the Multiple Sclerosis patient population.

A retrospective clinical outcome analysis of consecutive patients referred to a dedicated Multiple Sclerosis neuro-urological outpatient service for Neurogenic Overactive Bladder syndrome has been performed. Records from 2021 onwards were screened to include patients receiving Solifenacin at any stage of their urological therapeutic management. Patients without a uroflowmetry at first assessment and at least one follow-up appointment after the introduction of solifenacin were not included.

31 patients were included in the analysis, of which 22 (70.9%) were female. Median age was 51y (IQR 41;56) and median Multiple Sclerosis duration was 14y (IQR 3;19). 24 patients (77.4%) had relapsing remittent Multiple Sclerosis while 7 had a primary progressive disease type. Urgency urinary incontinence (UUI) was reported by 23 (74.2%) patients. Solifenacin was introduced as first-line therapy in 26 (83.8%) patients while it replaced either another anticholinergic or mirabegron in the remaining patients. A head-to-head comparison of clinical outcomes after the introduction of Solifenacin at a median follow-up of 12 mo (IQR 7;18) is shown in the Table. During treatment, a 16.2% rate of of Neurogenic Overactive Bladder syndrome resolution with Solifenacin was observed, while Urgency urinary incontinence was interrupted in 6/23 (26.1%) of the patients. The impact of Sol on uroflowmetry was overall negligible, and a direct comparison of uroflowmetry results in the 17 patients repeating the exam at follow-up showed comparable post-void residuals (PVR) (20 ml (IQR 0;50) at first assessment vs 20 ml (IQR 0;37.5) at follow-up). 6 Clavien-Dindo I adverse events were observed during treatment. Solifenacin was continued by 71% of the patients, of which 22.6% needed to increase the dosage to 10 mg per day to achieve adequate symptom control.

This low volume analysis showed a promising safety profile for Solifenacin in view of a negligible effect on post-void residuals (PVRs) and few therapy related adverse events. The therapeutic regimen was confirmed by the majority of patients as an effective symptomatic treatment, with complete symptom regression in some cases.

A high-volume prospective assessment of Solifenacin in the Multiple Sclerosis population is advocated to confirm the encouraging results of this analysis.