Utilization rate and long-term persistence of combination pharmacotherapy with β3-agonists and antimuscarinics for overactive bladder refractory to monotherapy in a real-world setting.

Aim: To assess real-world treatment profiles, including utilization rate, time to and reasons for discontinuation of combination pharmacotherapy with β -agonists and antimuscarinics for refractory overactive bladder (OAB) through a retrospective chart review.

Methods: We retrospectively reviewed the records of OAB patients who received β -agonists or antimuscarinics at our hospital between 2012 and 2020 and analyzed the clinical course of patients who progressed to combination therapy. Data on age, sex, major complaints, OAB symptom score at the initiation of combination therapy, treatment persistence, and reasons for discontinuation were collected. Treatment persistence was assessed with respect to the median time to discontinuation and persistence rate at 12 months.

Results: Of the 2163 patients receiving β -agonists or antimuscarinics, only 84 (3.8%) progressed to combination therapy with both drug classes. At therapy initiation, most (98%) of these patients had moderate to severe OAB symptoms. Median treatment duration and 12-month persistence rate for combination therapy were 595 days and 64.0%, respectively. The reasons for discontinuation were insufficient treatment efficacy followed by adverse effects including voiding impairment in nearly 10% of the patients. None of the baseline parameters was independently associated with persistence in the multivariate analysis.

Conclusion: While underutilized among OAB patients refractory to monotherapy, combination pharmacotherapy showed a greater persistence rate than published mirabegron or antimuscarinic monotherapy when applied to patients with moderate to severe symptoms. Treatment-emergent voiding impairment is a concern associated with this mode of therapy. A small sample size at a single institution is the limitation of this study.