Background: Antimuscarinics are often used for treatment of overactive bladder (OAB), but exposure to medications such as antimuscarinics that have anticholinergic properties has been linked to adverse cognitive effects. A phase 4 placebo-controlled study (PILLAR; NCT02216214) described the efficacy and safety of mirabegron, a β3-adrenoreceptor agonist, for treatment of wet OAB in patients aged ≥65 years. This pre-planned analysis aimed to measure differences in cognitive function between mirabegron and placebo, using a rapid screening instrument for mild cognitive impairment: the Montreal Cognitive Assessment (MoCA).
Methods: Outpatients aged ≥65 years with wet OAB were randomized 1:1 to mirabegron or placebo, stratified by age (<75/≥75 years). There were no exclusion criteria regarding cognitive status. Patients randomized to mirabegron initially received 25 mg/day with an optional increase to 50 mg/day after week 4/8 based on patient/investigator discretion. The MoCA was administered at baseline and end of treatment (EoT, week 12). The study protocol was Independent Ethics Committee/Institutional Review Board-approved.
Results: Of the 887 randomized patients who received ≥1 dose of study drug, 72.3% were female, 79.5% were white, and 28.1% were aged ≥75 years. All patients had ≥1 comorbidity and 94.3% were receiving ≥1 concomitant medication. One third of patients had a history of psychiatric disorders, the most common being depression (17.2%), insomnia (15.7%), and anxiety (11.4%). Baseline mean (standard error, SE) MoCA total scores were 26.9 (0.1) and 26.8 (0.1) in the mirabegron and placebo groups, respectively. Among patients with MoCA data available at baseline/EoT, 27.1% (115/425) and 25.8% (106/411) of mirabegron and placebo group patients, respectively, had impaired cognitive function at baseline (MoCA total score <26). There was no statistically significant change in adjusted mean (SE) MoCA total score from baseline to EoT in the mirabegron group (-0.2 [0.1]) or the placebo group (-0.1 [0.1]).
Conclusions: Treatment with mirabegron for 12 weeks did not contribute to drug-related cognitive side effects in patients aged ≥65 years, as measured by the MoCA. Furthermore, the pattern of change in cognition over time in an older OAB trial population does not appear to differ from that of subjects receiving placebo.
Trial registration: NCT02216214 (prospectively registered August 13, 2014).
Keywords: Aged; Clinical trial; Cognition; Elderly; Geriatric; Lower urinary tract symptoms; Overactive; Phase 4; Urinary bladder.