Mirabegron in the Treatment of Overactive Bladder: Safety and Efficacy in the Very Elderly Patient

Mirabegron 50 mg once daily, long-term treatment maximizes benefit in middle-aged and older people with overactive bladder syndrome: a systematic review and meta-analysis of nine phase II/III, randomized, double-blind, parallel-design, placebo-controlled, multicenter, and multinational trials

The prevalence and severity of overactive bladder increase with age, and mirabegron is an approved treatment for this condition. This meta-analysis systematically evaluated the efficacy and safety of mirabegron compared with placebo for overactive bladder treatment. We searched PubMed and the Cochrane Library (30 October 2023) for relevant articles (source: MEDLINE, EMBASE, ClinicalTrials.gov, ICTRP, CINAHL). We included randomized controlled trials involving adults with overactive bladder syndrome that compared mirabegron with placebo treatment. Data were analyzed according to the Cochrane Handbook for Systematic Reviews of Interventions [Review Manager (computer program) Version 5.4]. Nine parallel-group trials (10 articles) were included. The evaluation included a total of 8,527 adults, including 6,445 women and 2,082 men, of whom 5,726 were White, 2,462 were Asian, and 161 were Black. The mean age of the participants ranged from 53.4 to 60.3 years. This evaluation involved three specifications of mirabegron: 25 mg, 50 mg, and 100 mg. In all trials, patients were enrolled in a 12-week double-blind treatment period, and the dose was once daily. The review of trials found that on average, people taking mirabegron had about 13 ml more volume voided per micturition, five fewer micturitions, and four fewer incontinence episodes every week, with moderate improvements in quality of life. About one in five people taking the drug reported TRAEs. Mirabegron treatment is well tolerated, with the risk of adverse events similar to that of a placebo. For best results, a dose of 50 mg once daily is recommended for long-term use. It is unclear whether any benefits are sustained after treatment discontinuation. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, PROSPERO (CRD42023430737).

Posterior Tibial Nerve Stimulation With versus Without Mirabegron: A Randomized Controlled Trial

INTRODUCTION AND HYPOTHESIS

To compare change in urgency urinary incontinence episodes (UUIEs) in women undergoing posterior tibial nerve stimulation (PTNS) plus mirabegron versus PTNS plus placebo for the treatment of refractory urgency urinary incontinence (UUI). The primary hypothesis was that combination therapy is superior to monotherapy.

METHODS

A randomized controlled trial was performed in individuals identifying as female aged ≥ 18 years with UUI symptoms refractory to second-line treatment or who could not tolerate antimuscarinic medications. Both participants and providers were blinded to medication treatment allocation. Participants were randomized (1:1) to PTNS plus mirabegron or PTNS plus placebo. Participants completed a 3-day bladder diary prior to and after 12-week treatment. Validated symptom distress and impact questionnaires were obtained pre- and post-treatment. The primary outcome was change in mean number of UUIEs on a 3-day bladder diary pre- versus post-treatment between arms. Primary and secondary outcomes were analyzed via sample t tests.

RESULTS

Fifty-four subjects were randomized, mean ± SD baseline age 56.2±15.6 years and body mass index 35.0±9.4 (kg/m2); no differences were noted in any clinical-demographic characteristics. There was a significant difference between arms in mean pre- to post-treatment UUIEs, 9.4±3.9, mirabegron versus 5.3±5.5, placebo (p=0.007). Significant differences were found pre- compared with post-treatment in urinary frequency, Overactive Bladder Questionnaire Short Form Symptom Bother and Symptom Health-Related Quality of Life scores.

CONCLUSIONS

In subjects undergoing PTNS treatment for refractory UUI and OAB-wet symptoms, the addition of a β-3 agonist produced significant improvement in both objective and subjective overactive bladder symptom outcomes compared with PTNS plus placebo.

Cold stress-induced bladder overactivity in type 2 diabetic mellitus rats is mitigated by the combination of a M3 -muscarinic antagonist and a β3 -adrenergic agonist

OBJECTIVES

Goto-Kakizaki (GK) rats with type 2 diabetes mellitus respond to low temperature (LT) environments with bladder overactivity, including increased voiding frequency and decreased voiding interval and micturition volume. We determined if bladder overactivity could be inhibited by treatment with the combination of a M₃ -muscarinic receptor antagonist and a β₃ -adrenergic receptor agonist.

METHODS

Ten-week-old female GK rats were fed a high-fat diet for 4 weeks. Cystometric investigations were conducted at room temperature (RT, 27 ± 2°C). The rats were then intraperitoneally administered the vehicle, the M₃ -muscarinic receptor antagonist solifenacin, the β₃ -adrenergic agonist mirabegron, or a combination of solifenacin and mirabegron. Ten minutes after the administrations, the rats were transferred to the LT environment (4 ± 2°C), where the cystometric measurements were continued. The expressions of both M₃ -muscarinic and β₃ -adrenergic receptors were investigated.

RESULTS

After transfer from RT to LT, both voiding interval and bladder capacity of the vehicle-, solifenacin-, or mirabegron-treated rats were significantly decreased. However, the combination of solifenacin and mirabegron significantly mitigated the bladder overactivity. While both M₃ -muscarinic and β₃ -adrenergic receptors were detected, the expression of M₃ -muscarinic receptor mRNA was significantly higher than that of β₃ -adrenergic receptor mRNA.

CONCLUSIONS

The cold stress-induced bladder overactivity was not improved by either the M₃ -muscarinic receptor antagonist or the β₃ -adrenergic receptor agonist alone. However, the combined treatment mitigated the cold stress responses. Combined therapy with M₃ -muscarinic antagonists and β₃ -adrenergic agonists could reduce side effects and improve the quality of life for diabetic patients with bladder overactivity.

Impact of Mirabegron Administration on the Blood Pressure and Pulse Rate in Patients with Overactive Bladder

Background and Objectives: To determine changes in the blood pressure (BP) and pulse rate (PR) before and after the administration of mirabegron in real-world clinical practice for patients with overactive bladder (OAB). Materials and Methods: This study was conducted in patients newly diagnosed with OAB. Before and 12 weeks after mirabegron treatment, we evaluated the effects on BP and PR. An overall examination was conducted, and the patients were divided into two groups according to their age: a young group (<65 years old) and an old group (≥65 years old). Results: A total of 263 patients were enrolled in this study. In the overall and intragroup comparisons, the systolic BP (SBP) did not change significantly after mirabegron administration. However, an increase in SBP of ≥10 mmHg was observed in 53 (20.2%), 4 (7.4%), and 49 (23.4%) in the entire group, young group, and old group, respectively (p = 0.009). Regarding diastolic BP, a significant decrease after the treatment was detected in entire (71.2 ± 11.4 versus 69.8 ± 10.7 mmHg; p = 0.041) and old patients (71.5 ± 10.6 versus 69.5 ± 10.2 mmHg; p = 0.012). There was no significant change in PR in our study population. Further examination using a propensity match score revealed that age was the risk factor for the increase in SBP after mirabegron administration. Conclusions: Mirabegron does not have any adverse effects on BP and PR. However, since some patients in this study had elevated SBP after administration, we suggest regular BP monitoring during mirabegron treatment.

Anticholinergics and falls in older adults

INTRODUCTION

The use of medications with anticholinergic (ACh) properties is associated with numerous adverse effects especially in older adults. Emerging evidence suggests the presence of long-term effects with ACh use.

AREAS COVERED

Our article presents an overview of ACh effects and falls in older individuals including examination of emerging evidence on ACh use and cumulative exposure on short-term and long-term falls risk. The databases CINAHL, MEDLINE, EMBASE, and Web of Science were searched for articles published from January 2002 to December 2021.

EXPERT OPINION

Anticholinergic side effects include muscle weakness, blurred vision, and mental confusion which are likely to lead to increased falls risk. Many commonly used medications such as beta-blockers, calcium-channel blockers, and antihistamines are now known to have mild ACh properties. With polypharmacy now considered unavoidable in older patients, the cumulative effects of the use of multiple drugs with mild ACh properties may also lead to increased falls risk. The relationship between ACh drugs and falls may also be irreversible as ACh effects may extend beyond the period of drug use, due to cognitive and physical deconditioning following the initial exposure to ACh drugs. Future long-term studies with accurate quantification of cumulative ACh exposure and measurement of actual falls outcomes are urgently required.

A non-interventional cross-sectional re-contact study investigating the relationship between overactive bladder and frailty in older adults in Japan

Background

Increasing age is associated with frailty and a higher prevalence of overactive bladder (OAB). Given the rapidly increasing proportion of older adults in Japan, a better understanding of the relationship between frailty and OAB is needed to inform future healthcare planning. This study assessed the association between frailty and OAB in older adults in Japan and evaluated the impact on their health-related quality of life (HRQoL).

Methods

This was a cross-sectional re-contact study of respondents who previously completed the National Health and Wellness Survey 2018 in Japan. Participants were aged ≥65 years and Japanese speakers and readers. As part of a customized online survey, participants were screened for frailty using the Kihon Checklist (frail = scores ≥8 points) and OAB using the overactive bladder symptom score (OAB = total score ≥ 3 points and ≥ 2 points on question 3). The primary endpoint was the odds ratio of frailty in older adults with and without OAB assessed using a multivariable logistic regression model. Secondary endpoints were the prevalence rates of OAB and frailty. Exploratory endpoints assessed HRQoL using the Medical Outcomes Study 12-Item Short Form Survey Instrument version 2 (SF-12v2).

Results

Overall, 2953 participants were included: 150 (5.1%) were frail OAB, 416 (14.1%) non-frail OAB, 287 (9.7%) frail non-OAB, and 2100 (71.1%) non-frail non-OAB. There was a statistically significant correlation between frailty and OAB demonstrated by an adjusted odds ratio (95% CI) of 2.78 (2.18–3.54; p <  0.001). The prevalence (95% CI) of OAB was 34.3% (29.9–38.8) in frail and 16.5% (15.1–18.0) in non-frail older adults; the prevalence of frailty was 26.5% (22.9–30.1) and 12.0% (10.7–13.3) in older adults with and without OAB. HRQoL was assessed in 150 participants per group. The adjusted HRQoL analyses showed significantly lower scores in participants who were frail OAB vs. frail non-OAB for most of the SF-12v2 scores/sub-component scores.

Conclusions

These data highlight the statistically significant positive correlation between frailty and OAB among older adults in Japan and may provide valuable information on the burden of OAB and frailty on older adults to healthcare professionals when considering future healthcare planning.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02756-7.

Managing Nocturia in Frail Older Adults

This review discusses the available evidence in the current evaluation and treatment of nocturia in frail older adults. No evidence specifically evaluates the use of behavioral interventions in the treatment of the frail older adult with nocturia, but their use is supported in other cohorts. Behavioral modifications and optimal management of comorbidities remain the first-line treatment for all age groups and should be emphasized in the frail due to their favorable safety profile. No studies specific to the frail older adult support the use of pharmacotherapy. Some evidence exists for the efficacy of several agents in the older adult; however, this is difficult to extrapolate to the frail, and safety concerns abound. Desmopressin may be effective in the older adult, but a high risk of hyponatremia raises concerns for its safety, and therefore it is not recommended in the frail. α-Antagonists may have limited efficacy in men with known benign prostatic hyperplasia (BPH); they are relatively well tolerated, although the risk of orthostatic hypotension in the frail should be considered. β3-agonist trials suggest limited clinical utility. Antimuscarinics are not found to be useful in this cohort and are contraindicated in the frail older adult given the ability of antimuscarinics to cause cognitive impairment, delirium, and falls. No data examine the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in the frail older adult. Additionally, the American Geriatrics Society Beers Criteria recommends against the use of muscarinics in those over the age of 75 years and therefore their use is not supported.