MP17-08 EFFICACY AND TOLERABILITY OF MIRABEGRON IN MULTIPLE SCLEROSIS: A PROSPECTIVE ANALYSIS

INTRODUCTION AND OBJECTIVES: Approximately 80% of Multiple Sclerosis (MS) patients are affected by bladder dysfunction. Most experience overactive bladder (OAB) symptoms. Management is complicated by the high prevalence (43-74%) of concomitant bowel dysfunction. Anticholinergics, traditionally used in the treatment of OAB symptoms in MS, have side effects including dry mouth, constipation and cognitive impairment. Mirabegron, a Beta 3 agonist, is now used for idiopathic OAB. It has a different mechanism of action and side effect profile. Our aim was to determine whether mirabegron would be effective in MS patients without negatively affecting bowel function METHODS: We prospectively surveyed MS patients presenting to our MS center with OAB symptoms. At the baseline and 6 week follow up visit, we collected post void residuals (PVR), blood pressure (BP), demographics and standardized questionnaires. These include the Overactive Bladder Questionnaire (OAB-q), Patient Global Impression of Severity (PGI-S), Urinary Distress Inventory (UDI -6) and PACSYM (Patient Assessment of Constipation Symptoms). Paired Ttest and multivariable logistic regression were performed using SAS software RESULTS: 25 patients were enrolled, with 13 patients completing follow-up at time of analysis. Mean age was 51.7( 9.1). 39% were male. Mean duration of MS diagnosis was 10 ( 7.6) years. 92% complained of baseline constipation. At 6 weeks there was a significant improvement in bowel function (p1⁄4 0.037) and OAB symptoms (p1⁄40.000) (figure 1). The mean improvement in PAC-SYM score was 1.46, a clinically significant difference based on prior validating studies. There was significant improvement in PGI-S (p1⁄40.01), with most reporting symptoms as “much better”. BP elevation, urinary retention, dry mouth, fatigue and cognitive impairment were not observed. CONCLUSIONS: In this pilot study, mirabegron seems effective for the management of OAB in MS patients with no tolerability issues. It is notable that patients actually experienced an improvement in constipation. The sample size is small and no control group was used. However the findings are encouraging and show the need for larger controlled trials of beta3 agonists in MS patients to explore the potential improvement in bowel function. Source of Funding: none