Real-World Effects of Mirabegron in Patients with Chronic Neurogenic Detrusor Overactivity – A Retrospective Cohort Study

PURPOSE: To investigate the tolerability and the effects of the β-3-adrenoceptor-agonist mirabegron on urinary incontinence and urodynamic parameters in patients with chronic neurogenic detrusor overactivity (NDO). PATIENTS AND METHODS: The patient database of a spinal cord injury rehabilitation center in Switzerland was screened for patients with chronic (>12 months) NDO, who had been prescribed mirabegron. Patient characteristics, data regarding bladder management, urinary incontinence and concurrent medication for NDO as well as urodynamic parameters were collected retrospectively. The changes in the urodynamic parameters and the occurrence of urinary incontinence over time were investigated. RESULTS: The data of 63 patients with a median age of 48 years and a median NDO duration of 8.9 years at the initiation of the mirabegron treatment were analyzed. A median 3.0 and 12.7 months had elapsed from the initiation of the mirabegron therapy to the first and second follow-up evaluation, respectively. The majority of patients (73%) received mirabegron in combination with an established antimuscarinic or onabotulinum toxin therapy. The number of patients suffering from urinary incontinence decreased significantly (p≤0.005) from 60.3% (95% CI 47.2/72.4%) to 38.1% (95% CI 23.6/54.4%). Furthermore, the maximum detrusor pressure during the storage phase was significantly (p≤0.04) lower at the second follow-up evaluation (29.5cmH(2)O, 95% CI 22/40cmH(2)O) compared to before the mirabegron treatment (35cmH(2)O, 95% CI 29/41cmH(2)O). The bladder capacity and detrusor compliance were significantly (p≤0.005) increased during the mirabegron treatment. No patient had discontinued the mirabegron treatment as a result of side effects. CONCLUSION: Mirabegron demonstrated a clinically relevant effect and a good safety profile. Concomitant treatment of NDO with mirabegron may allow reduction in the dose of antimuscarinic medication and thus, improve the long-term persistence of NDO treatment.