Purpose: This study aimed to measure the cumulative anticholinergic burden in older outpatients in South Korea with and without newly started overactive bladder (OAB) medications, and to assess the contribution OAB treatment-related antimuscarinics have on overall anticholinergic exposure.
Methods: This retrospective study utilizing the South Korean National Health Insurance Service database included patients ≥65 years old with ≥1 outpatient visit (any cause) between January 1 and June 30, 2016. The overall cohort included patients with OAB and matched patients without OAB. Outcomes were assessed over a 100-day follow-up period. Primary endpoints were 100-day cumulative anticholinergic cognitive burden score, prevalence of anticholinergic and strong anticholinergic use, and number of anticholinergics per patient. Proportion of anticholinergic cognitive burden score attributable to OAB medication was a secondary endpoint.
Results: The final study cohort included 2,360 patients with OAB and 11,676 patients without OAB. Mean 100-day cumulative anticholinergic cognitive burden score was 15.2 times higher for OAB (320.1) than non-OAB (21.0). Anticholinergics were used widely for OAB patients (2,287 [96.9%] vs. 3,921 [33.6%] non-OAB patients). Prevalence of strong anticholinergic use was almost 4 times higher for OAB (2,234 patients [94.7%]) compared with non-OAB (2,817 patients [24.1%]). On average, 0.9 anticholinergics were dispensed per patient. Anticholinergic cognitive burden score attributable to OAB medications was 66.9% in the antimuscarinic-only group, 64.3% in the antimuscarinic with mirabegron group, and 0% in the mirabegron-only group.
Conclusion: In patients with OAB, 100-day cumulative anticholinergic cognitive burden score was 15 times higher than in patients without OAB, due to anticholinergic medications. In this study, mirabegron did not contribute to anticholinergic burden. As there are unwanted effects associated with this burden, clinicians should consider the anticholinergic burden of each patient when using pharmacotherapy to treat OAB.
Keywords: Antimuscarinics; Mirabegron; Overactive bladder.