The role of mirabegron in overactive bladder: a systematic review and meta-analysis

Mirabegron Versus Placebo and Other Therapeutic Modalities in the Treatment of Patients with Overactive Bladder Syndrome-A Systematic Review

BACKGROUND AND OBJECTIVE

The prevalence of overactive bladder (OAB) increases with age. Mirabegron and other drugs are used for the management of patients with OAB. To evaluate mirabegron versus other treatments for overactive bladder syndrome (OAB).

METHODS

This randomised controlled trial (RCT)-based systematic review (CRD42020200394) was conducted following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analyses statement, with standards reported in the Cochrane Handbook for Systematic Reviews of Interventions.

KEY FINDINGS AND LIMITATIONS

We included 28 RCTs (n = 27 481 adults), comparing the following: mirabegron 25 mg versus placebo (n = 8798; six RCTs): significant changes in urgency urinary incontinence (mean difference [MD] -0.41, 95% confidence interval [CI] -0.56 to -0.26), total incontinence (MD -0.47, 95% CI -0.63 to -0.30), and nocturia (MD -0.10, 95% CI -0.17 to -0.02), and mirabegron 50 mg versus placebo (n = 14 933; 12 RCTs): significant changes in urgency urinary incontinence (MD -0.41, 95% CI -0.52 to -0.31), urgency (MD -0.49, 95% CI -0.64 to -0.33), total incontinence (MD -0.44, 95% CI -0.55 to -0.33), favouring mirabegron 25/50 mg; mirabegron 50 mg versus tolterodine 4 mg (n = 8008; five RCTs): significant changes in micturition (MD -0.16, 95% CI -0.31 to -0.02) and overall adverse events (AEs; odds ratio [OR] 0.71, 95% CI 0.59-0.86), favouring mirabegron 50 mg; mirabegron 50 mg versus solifenacin 5 mg (n = 8911; four RCTs): significant changes in voided volume/micturition in millilitres (MD -7.77, 95% CI -12.93 to -2.61), favouring mirabegron 50 mg; and mirabegron 50 mg versus oxybutynin 73.5 mg (n = 302; one RCT): significant changes in overall AEs (OR 0.02, 95% CI 0.00-0.16), favouring mirabegron 50 mg.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Mirabegron is effective, safe, and well tolerated. Coadministration with anticholinergics provides an advantageous additive effect without a higher occurrence of side effects.

PATIENT SUMMARY

Mirabegron is effective, safe, and well tolerated for treating overactive bladder. When used in conjunction with anticholinergic medications, it provides extra benefits without causing more side effects.

Ligand-Receptor Interactions and Structure-Function Relationships in Off-Target Binding of the β3-Adrenergic Agonist Mirabegron to α1A-Adrenergic Receptors

The β3-adrenoceptor agonist mirabegron is available for the treatment of storage symptoms of overactive bladder, including frequency, urgency, and incontinence. The off-target effects of mirabegron include binding to α1-adrenoceptors, which are central in the treatment of voiding symptoms. Here, we examined the structure-function relationships in the binding of mirabegron to a cryo-electron microscopy structure of α1A. The binding was simulated by docking mirabegron to a 3D structure of a human α1A-adrenoceptor (7YMH) using Autodock Vina. The simulations identified two binding states: slope orientation involving 10 positions and horizontal binding to the receptor surface involving 4 positions. No interactions occurred with positions constituting the α1A binding pocket, including Asp-106, Ser-188, or Phe-312, despite the positioning of the phenylethanolamine moiety in transmembrane regions close to the binding pocket by contact with Phe-288, -289, and Val-107. Contact with the unique positions of α1A included the transmembrane Met-292 during slope binding and exosite Phe-86 during horizontal binding. Exosite binding in slope orientation involved contact of the anilino part, rather than the aminothiazol end, to Ile-178, Ala-103, and Asn-179. In conclusion, contact with Met-292 and Phe-86, which are unique positions of α1A, accounts for mirabegron binding to α1A. Because of its lack of interactions with the binding pocket, mirabegron has lower affinity compared to α1A-blockers and no effects on voiding symptoms.

Safety and efficacy of an α1 -blocker plus mirabegron compared with an α1 -blocker plus antimuscarinic in men with lower urinary tract symptoms secondary to benign prostatic hyperplasia and overactive bladder: A systematic review and network meta-analysis

AIM

Antimuscarinics and the β3-adrenoreceptor agonist, mirabegron, are commonly used for treating patients with overactive bladder (OAB) and α1 -adrenoreceptor antagonists (α1 -blockers) are the main pharmacological agents used for treating lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). As these conditions commonly occur together, the aim of this systematic review was to identify publications that compared the use of an α1 -blocker plus mirabegron with an α1 -blocker plus antimuscarinic in men with LUTS secondary to BPH and OAB. A meta-analysis was subsequently conducted to explore the safety and efficacy of these combinations.

METHODS

Included records had to be from a parallel-group, randomized clinical trial that was ≥8 weeks in duration. Participants were male with LUTS secondary to BPH and OAB. The indirect analyses that were identified compared an α1 -blocker plus OAB agent with an α1 -blocker plus placebo. The PubMed/Medical Literature Analysis and Retrieval System Online, the Excerpta Medica Database, the Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov registry were searched for relevant records up until March 5, 2020. Safety outcomes included incidences of overall treatment-emergent adverse events (TEAEs) and urinary retention, postvoid residual volume, and maximum urinary flow (Qmax ). Primary efficacy outcomes were micturitions/day, incontinence episodes/day, and urgency episodes/day, and secondary outcomes were Overactive Bladder Symptom Score and International Prostate Symptom Score. A Bayesian network meta-analysis approach was used for the meta-analysis.

RESULTS

Out of a total of 1039 records identified, 24 were eligible for inclusion in the meta-analysis. There were no statistically significant differences between the α1 -blocker plus mirabegron and α1 -blocker plus antimuscarinic groups in terms of the comparisons identified for all the safety and efficacy analyses conducted. Numerically superior results were frequently observed for the α1 -blocker plus mirabegron group compared with the α1 -blocker plus antimuscarinic group for the safety parameters, including TEAEs, urinary retention, and Qmax . For some of the efficacy parameters, most notably micturitions/day, numerically superior results were noted for the α1 -blocker plus antimuscarinic group. Inconsistency in reporting and study variability were noted in the included records, which hindered data interpretation.

CONCLUSION

This systematic review and meta-analysis showed that an α1 -blocker plus mirabegron and an α1 -blocker plus antimuscarinic have similar safety and efficacy profiles in male patients with LUTS secondary to BPH and OAB. Patients may, therefore, benefit from the use of either combination within the clinical setting.

Design of screen-printed potentiometric platform for sensitive determination of mirabegron in spiked human plasma; molecular docking and transducer optimization

The integration of molecular modelling simulation and electrochemical sensors is of high interest. Herein, for the first time, a portable solid-contact potentiometric electrode was designed for the sensitive determination of mirabegron (MIR) in human plasma and pharmaceutical formulation. A two-step optimization protocol was investigated for the fabrication of an ion on sensing polymeric membrane. First, molecular docking was used for optimum ionophore selection. Calix[6]arene showed the highest affinity towards MIR with a better docking score (-4.35) and potential energy (-65.23) compared to other calixarene derivatives. Second, carbon nanotubes and gold nanoparticles were investigated as ion-electron transducers using a drop-casting procedure. Gold nanoparticle-based sensors showed better slope, potential stability, and rapid response compared to carbon nanotubes. The proposed solid contact sensors (V-VII) showed comparable sensitivity and ease of handling compared to liquid contact sensors (I-IV). The optimized gold nanoparticles sensor VII produced a Nernstian response over the range of 9.77 × 10-7 to 1 × 10-3 M with LOD of 2.4 × 10-7 M. It has also been used to determine MIR in its pharmaceutical formulation in the presence of a co-formulated antioxidant butylated hydroxytoluene and spiked human plasma. This would offer a feasible and economic platform for monitoring MIR in pharmaceutical preparation and biological fluids.

The Efficiency and Safety of Mirabegron Monotherapy for the Treatment of Urge Incontinence in Women Aged >80 Years

Objective We aimed to evaluate the efficacy and safety of mirabegron monotherapy in very older (>80 years) women with overactive bladder (OAB) who were discontinued anticholinergic drugs by the other departments. Material and methods The present retrospective study evaluated very older (>80 years) women with OAB who were discontinued anticholinergic drugs by the other departments between May 2018 and January 2021. Efficacy assessments were performed using Overactive Bladder-Validated Eight-Question (OAB-V8) scores before and after mirabegron monotherapy (12 weeks). Safety was evaluated based on adverse events (hypertension, nasopharyngitis, and urinary tract infection), electrocardiography, hypertension measure, uroflowmetry (UFM), and post-voiding. Patient data including demographic characteristics, diagnoses, values before and after mirabegron monotherapy, and adverse events were evaluated. Results A total of 42 very older (>80 years) women with OAB who used mirabegron monotherapy (50 mg per day) were included in this study. Frequency, nocturia, urgency, and total OAB-V8 scores were significantly lower after mirabegron monotherapy than before mirabegron monotherapy (p < 0.05, p < 0.05, p < 0.05, and p < 0.05, respectively). There was no significant difference between systolic-diastolic blood pressure and heart rate before and after mirabegron monotherapy treatment. Conclusion Mirabegron monotherapy is an effective and safe therapy in very older (>80 years) women with OAB.

European Association of Urology Guidelines on the Diagnosis and Management of Female Non-neurogenic Lower Urinary Tract Symptoms. Part 1: Diagnostics, Overactive Bladder, Stress Urinary Incontinence, and Mixed Urinary Incontinence

CONTEXT

Female lower urinary tract symptoms (LUTS) are a common presentation in urological practice. Thus far, only a limited number of female LUTS conditions have been included in the European Association of Urology (EAU) guidelines compendium. The new non-neurogenic female LUTS guideline expands the remit to include these symptoms and conditions.

OBJECTIVE

To summarise the diagnostic section of the non-neurogenic female LUTS guideline and the management of female overactive bladder (OAB), stress urinary incontinence (SUI), and mixed urinary incontinence (MUI).

EVIDENCE ACQUISITION

New literature searches were carried out in September 2021 and evidence synthesis was conducted using the modified GRADE criteria as outlined for all EAU guidelines. A new systematic review (SR) on OAB was carried out by the panel for the purposes of this guideline.

EVIDENCE SYNTHESIS

The important considerations for informing guideline recommendations are presented, along with a summary of all the guideline recommendations.

CONCLUSIONS

Non-neurogenic female LUTS are an important cause of urological dysfunction. Initial evaluation, diagnosis, and management should be carried out in a structured and logical fashion based on the best available evidence. This guideline serves to present this evidence to health care providers in an easily accessible and digestible format.

PATIENT SUMMARY

This report summarises the main recommendations from the European Association of Urology guideline on symptoms and diseases of the female lower urinary tract (bladder and urethra) not associated with neurological disease. We cover recommendations related to diagnosis of these conditions, as well as the treatment of overactive bladder, stress urinary incontinence, and mixed urinary incontinence.

The clinical pharmacology of the medical treatment for overactive bladder in adults

INTRODUCTION

Overactive bladder is a prevalent symptom complex that affects the patient's quality of life. Any disruption between the neuronal micturition pathway can lead to bladder overactivity. Neurogenic causes, myogenic causes, aging, bladder outlet obstruction, sex, and psychological factors are some of the factors contributing to bladder overactivity. The complaint of any symptoms of OAB, which is highly prevalent and affects overall QOL, often needs therapeutic interventions. When conservative therapy methods fail, the addition of medications is recommended. The most commonly used agents for the treatment of OAB are antimuscarinic drugs. New classes of drugs, such as beta-3 agonists, have enriched our pharmacologic armamentarium.

AREAS COVERED

In this review, with a special focus on oral pharmacological treatments, we discussed the definition, etiology, symptoms, diagnosis, and management of OAB.

EXPERT OPINION

OAB is a multifactorial condition with every patient presenting with a different collection of symptoms and signs. Medical therapies should be given in conjunction with behavioral therapies. Using high or low doses, flexible doses, and stopping or changing the medications are interchangeable strategies based on the level of treatment efficacy and patient satisfaction.

Mirabegron is alternative to antimuscarinic agents for overactive bladder without higher risk in hypertension: a systematic review and meta-analysis

PURPOSE

Mirabegron, a β3-adrenoceptor agonist, was approved for overactive bladder (OAB), but worsened hypertension was a potential risk based on its mechanism of action. Besides, head to head comparisons were limited between mirabegron and antimuscarinic agents, the prior first-line pharmacotherapy of OAB. In this regard, we performed a systematic review and meta-analysis to compare their efficacy as well as safety, especially in blood pressure changes.

MATERIALS AND METHODS

Literature search was conducted in PubMed, Medline and seven randomized clinical trial (RCT) register databases of WHO, EU, USA, Taiwan, China, Japan and Cochrane. Completed RCTs for OAB with mirabegron and antimuscarinics were identified and the last comprehensive search was run in August 2017. Cochrane risk of bias tool was used to assess the potential bias, and RevMan5 software was performed for meta-analysis.

RESULTS

Seven eligible RCTs (four for mirabegron vs. tolterodine and three for mirabegron vs. solifenacin) were included and demonstrated similar efficacy in micturitions, incontinence, and nocturia between mirabegron and antimuscarinics. In hypertension issue, no statistical differences were showed in risk ratio (RR) of hypertension events, change of blood pressure from baseline and change of blood pressure from placebo for all participants. On the other hand, RR of dry mouth was significantly lower in mirabegron users.

CONCLUSIONS

Mirabegron was not inferior effective in improving OAB symptoms compared with antimuscarinic agents. In addition, mirabegron presented lower incidence of dry mouth and not higher risk for hypertension. Therefore, mirabegron has potential to be an alternative therapeutic option for OAB control.

EAU Guidelines on Assessment and Nonsurgical Management of Urinary Incontinence

CONTEXT

The European Association of Urology guidelines on urinary incontinence (UI) have been updated in cyclical fashion with successive major chapters being revised each year. The sections on assessment, diagnosis, and nonsurgical treatment have been updated as of mid-2016.

OBJECTIVE

We present a condensed version of the full guideline on assessment and nonsurgical management of UI, with the aim of improving accessibility and increasing their dissemination.

EVIDENCE ACQUISITION

Our literature search was updated from the previous cut-off of July 2010 up to April 2016. Evidence synthesis was carried out by a pragmatic review of current systematic reviews and any newer subsequent high-quality studies, based on Population, Interevention, Comparator, and Outcome questions. Appraisal was conducted by an international panel of experts, working on a strictly nonprofit and voluntary basis, to develop concise evidence statements and action-based recommendations using modified Oxford and GRADE criteria.

EVIDENCE SYNTHESIS

The guidelines include algorithms that summarise the suggested pathway for standard, uncomplicated patients with UI and are more useable in daily practice. The full version of the guideline is available at http://uroweb.org/guideline/urinary-incontinence/.

CONCLUSIONS

These updated guidelines provide an evidence-based summary of the assessment and nonsurgical management of UI, together with a clear clinical algorithm and action-based recommendations. Although these guidelines are applicable to a standard patient, it must be remembered that therapy should always be tailored to individual patients' needs and circumstances.

PATIENT SUMMARY

Urinary incontinence is a very common condition which negatively impacts patient's quality of life. Several types of incontinence exist and since the treatments will vary, it is important that the diagnostic evaluation establishes which type is present. The diagnosis should also identify patients who need rapid referral to an appropriate specialist. These guidelines aim to provide sensible and practical evidence-based guidance on the clinical problem of urinary incontinence.

Mirabegron Toxicosis in Dogs: a Retrospective Study

Mirabegron is a selective beta (B)₃ adrenoreceptor agonist marketed for human treatment of an overactive bladder (OAB). It has a wide margin of safety in humans, but in dogs, severe adverse effects have occurred. We sought to determine the effects and outcome of mirabegron toxicosis in dogs. A retrospective review of all calls within the Pet Poison Helpline (PPH), an international animal poison control center, database was performed for mirabegron exposures between 2013 and 2015. Potential ingested doses ranging from 1.31 to 8.3 mg/kg. Many dogs remained asymptomatic and no fatalities occurred in any dogs. The most commonly reported signs were tachycardia and erythema. While mirabegron was found to have a very narrow margin of safety and high toxicity risk to dogs during preclinical trials, effects appear to differ greatly in the nonclinical field environment and further study is needed.

No. 353-Treatments for Overactive Bladder: Focus on Pharmacotherapy - An Addendum

OBJECTIVE

This technical update addendum reviews success rates and comparative evidence of the anticholinergic fesoterodine, as well as mechanism of action, safety profile, success rates, and comparative evidence of the β3 agonist mirabegron in the treatment of non-neurogenic overactive bladder syndrome (OAB). This adds to OAB pharmacotherapy recommendations initially published in 2012.

INTENDED USERS

Residents and other trainees, primary care practitioners, gynaecologists, urologists, urogynaecologists, and other health care providers who assess, counsel, and treat women with OAB.

TARGET POPULATION

Adult women with symptomatic OAB.

OPTIONS

This addition relates to fesoterodine, mirabegron, and anticholinergic-β3 agonist combination pharmacotherapy.

OUTCOMES

The outcomes of interest are clinical efficacy of fesoterodine compared with no treatment or other OAB therapies; mechanism of action and safety profile of mirabegron, clinical efficacy of mirabegron compared to no treatment or other OAB therapies; clinical efficacy of anticholinergic-β3 agonist combination pharmacotherapy for OAB.

EVIDENCE

PubMed, Medline, and the Cochrane Database were searched using the key words "fesoterodine" and "mirabegron." Results were restricted to English or French and human clinical and pharmacological research. Animal research and clinical studies including only male participants were excluded. Articles were included until the end of December 2016. Grey literature was not searched. Clinical practice guidelines, guidelines of specialty societies, and systematic reviews were included. RCTs and observational studies were included when evidence for the outcome of interest or in the target population was not available from systematic reviews. New studies not yet included in systematic reviews were also included. References of included articles were also searched to ensure comprehensive inclusion of relevant literature.

VALUES

The content and recommendations were drafted and agreed upon by the principal author, as well as members of the Urogynaecology Committee. The Board of the SOGC approved the final draft for publication. The quality of evidence was rated using the criteria described in the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology framework. The Summary of Findings is available upon request.

BENEFITS, HARMS, AND/OR COSTS

It is expected that this technical update will benefit patients with OAB by providing physicians and other interested health care providers with additional options for and knowledge of safe and effective OAB pharmacotherapy. The benefits clearly outweigh the potential harms or costs of implementation of this technical update, although there are no direct harms or costs identified. UPDATES: "Evidence will be reviewed 5 years after publication to decide whether all or part of the document should be updated. However, if important new evidence is published prior to the 5-year cycle, the review process may be accelerated for a more rapid update of some recommendations."

SPONSORS

Not applicable.

RECOMMENDATIONS

Safety issues associated with using medication to treat overactive bladder

INTRODUCTION

The mainstay of overactive bladder treatment is the use of anticholinergic medication with its common side effects well known. This review focused on three less well-known safety issues when treating OAB. Areas covered: Patients with increased anticholinergic load are at risk of cognitive decline, dementia or even death. The elderly are particularly at risk due to polypharmacy. Botulinum toxin carries the risk of high urinary residuals, urinary tract infection and need to self catheterise. The use of vaginal oestrogens may improve OAB symptoms, but there is concern in those with a history of breast cancer. Studies have shown that the systemic absorption is negligible and does not increase the risk of recurrence. Expert Opinion: Improvement in assessing anticholinergic load is needed with the development of a universal drug scale. To avoid increasing load, Mirabegron or botulinum toxin can be used instead. There is no consensus of the use of prophylactic antibiotics when injecting botulinum toxin and at what residual to initiate self catheterisation. Despite evidence showing that the use of vaginal oestrogens is safe in those with a history of cancer, it is not fully supported by any health body. Further work is needed in those using aromatase inhibitors.

Comparative assessment of the efficacy of onabotulinumtoxinA and oral therapies (anticholinergics and mirabegron) for overactive bladder: a systematic review and network meta-analysis

OBJECTIVES

To compare the efficacy of onabotulinumtoxinA, mirabegron, and anticholinergics in adults with idiopathic overactive bladder (OAB) using network meta-analysis (NMA).

PATIENTS AND METHODS

Information sources were searched for blinded randomised controlled trials (RCTs), of ≥2 weeks duration, comparing any dose of onabotulinumtoxinA, eligible oral/transdermal anticholinergics, or mirabegron, with each other or placebo, in adults with OAB. Bayesian random-effects models were used to synthesise the results at week 12: NMA for responder analyses and network meta-regression (NMR) for change from baseline analyses. The NMR was used to adjust for differences in baseline severity between studies. Sensitivity analysis, excluding studies considered to be at a high risk of methodological bias, was conducted.

RESULTS

In all, 56 RCTs were included in the networks. For each outcome, results are reported for all licensed treatment doses. For each NMR, results are based on patients with an average number of episodes of the outcome at baseline. After 12 weeks, all treatments were more efficacious than placebo. Patients who received onabotulinumtoxinA (100 U) had, on average, the greatest reductions in urinary incontinence episodes (UIE), urgency episodes, and micturition frequency, and the highest odds of achieving decreases of 100% and ≥50% from baseline in UIE/day. When comparing onabotulinumtoxinA with other pharmacotherapies, mean differences favoured onabotulinumtoxinA 100 U over all comparators for UIE and urgency episodes (credible intervals excluded zero) and all but two of the comparators for micturition frequency. OnabotulinumtoxinA 100 U was also associated with higher odds of achieving a 100% and ≥50% decrease in UIE/day than most other licensed treatments in the network. The exclusion of studies with a high risk of bias had little impact on the conclusions.

CONCLUSION

The results indicate that, after 12 weeks, onabotulinumtoxinA 100 U provides greater relief of OAB symptoms compared with most other licensed doses of other pharmacotherapies in the network.

Evaluating the efficacy and tolerability of mirabegron, a β3-adrenoceptor agonist, for the treatment of overactive bladder: Systematic review and network meta-analysis

Purpose:

Overactive bladder (OAB) is a common condition affecting approximately 11% of individuals worldwide. One of the newest treatment options for OAB symptoms is mirabegron. The objective of this network meta-analysis is to evaluate the extent of the efficacy and tolerability of mirabegron compared both to placebo and first-line anticholinergic pharmacotherapies.

Methods:

Articles were identified through the MEDLINE, EMBASE, and Cochrane databases using the search term ‘mirabegron’. All original, prospective, randomised, controlled, double-blind clinical trials studying mirabegron in adults receiving initial treatment for OAB were included. Efficacy was assessed based on outcome variables and responder data. Tolerability was evaluated for reported adverse events.

Results:

Thirteen studies including a total of 13,333 individuals were included. Mirabegron demonstrated better efficacy compared to placebo and tolterodine extended release 4 mg. Compared to placebo, the incidence of tachycardia and nasopharyngitis was greater with mirabegron 50 mg, and the incidence of cardiac arrhythmia was greater in 100 mg treatment groups. Mirabegron 100 mg also demonstrated a lower incidence of cardiac arrhythmia compared to tolterodine.

Conclusions:

The current study presents new information that may affect patient-centred strategies for the management of OAB, with a particular concern for cardiovascular safety.

Mixed urinary incontinence- what should we treat first?

Mixed urinary incontinence (MUI) is defined as ‘the involuntary loss of urine associated with urgency and also with effort or physical exertion, or on sneezing or coughing’. It is highly prevalent, increases with age and affects women more than men. It has a significant negative impact on health-related quality of life (HRQL). Additionally, treatment of mixed urinary incontinence places a large financial burden on both individuals and the NHS. Optimal management of this common condition is contested – should we treat the urge urinary incontinence (UUI), stress urinary incontinence (SUI) or predominant symptom first? At the 2015 BAUS Section of Female, Neurological and Urodynamic Urology this subject was debated. Based on a common scenario, the authors of the debate present the arguments for treating the urge urinary incontinence component, stress urinary incontinence component or the predominant symptom of mixed urinary incontinence first, before making recommendations for current practice.

Adverse events and treatment discontinuations of antimuscarinics for the treatment of overactive bladder in older adults: A systematic review and meta-analysis

INTRODUCTION

Antimuscarinics should be used with caution in older adults with overactive bladder (OAB) due to anticholinergic adverse events (AEs). Systematic reviews and meta-analyses (SRMAs) have analyzed safety-related outcomes but have not specified risk in the elderly, the population at highest risk for AEs. The aim of this review is to explore and evaluate AEs and treatment discontinuations in adults 65 or older taking antimuscarinics for OAB.

METHODS

Keywords were searched in MEDLINE, EMBASE, SCOPUS, and Cochrane Central Register for Controlled Trials. Randomized controlled trials (RCTs) along with sub-analyses and pooled analyses that compared antimuscarinics to placebo or another antimuscarinic were performed in February 2015. Studies assessing AEs or treatment discontinuations in a population of adults 65 or older were included. The Jadad Criteria and McHarm Tool were used to assess the quality of the trials.

RESULTS

A total of 16 studies met the inclusion criteria. Eighty AEs and 27 reasons for treatment discontinuation were described in the included studies and further explored. Anticholinergic AEs were more common in antimuscarinics compared to placebo. Incidence of dizziness, dyspepsia, and urinary retention with fesoterodine, headache with darifenacin, and urinary tract infections with solifenacin were significantly higher compared to placebo. Treatment discontinuation due to AEs and dry mouth were higher in the antimuscarinics when compared to placebo in older adults.

CONCLUSIONS

Treatment for overactive bladder using antimuscarinics in adults aged 65 or older resulted in significant increases in risk for several AEs compared to placebo including anticholinergic and non-anticholinergic AEs.

Safety and tolerability of β3-adrenoceptor agonists in the treatment of overactive bladder syndrome - insight from transcriptosome and experimental studies

INTRODUCTION

We have reviewed the safety and tolerability of β3-adrenoceptor agonists, specifically mirabegron and solabegron, a newly emerging drug class for the treatment of the overactive bladder syndrome. We discuss them mechanistically in the context of expression and other preclinical data.

AREAS COVERED

Based on a systematic PubMed search, incidence of overall adverse events, hypertension, dry mouth, and constipation are comparable between mirabegron or solabegron and placebo. Hypertension is the most frequently observed adverse event, but has a similar incidence with mirabegron and placebo. Nevertheless, severe uncontrolled hypertension has become a contraindication for use of mirabegron based on observation of severe hypertension in association with mirabegron exposure. The overall incidence of adverse events is also similar between mirabegron and the muscarinic receptor antagonist tolterodine, but the incidence of dry mouth is much lower with mirabegron.

EXPERT OPINION

The high β3-adrenoceptor mRNA expression in the human ovaries is not associated with reproductive side effects. Generally, β3-adrenoceptors exhibit a rather restricted expression in human tissues, which may explain the overall good tolerability of agonists acting on this receptor. We propose that expression profiles and functional preclinical studies can be important tools in the prediction of adverse event profiles in first-in-class drugs.

The efficacy and tolerability of mirabegron, a β3 adrenoceptor agonist, in patients with symptoms of overactive bladder

Mirabegron, is the only β-3 adrenoreceptor (AR) agonist available for the treatment of overactive bladder (OAB). To assess the efficacy and tolerability of this novel drug therapy, two phase II and six phase III Astellas-sponsored trials have been conducted with over 10,500 adults with OAB recruited. Of these, seven were randomized, double blind, 12-week placebo controlled studies and the other was for 12 months and not placebo controlled. The evidence described would suggest that mirabegron is as efficacious as most antimuscarinics, including tolterodine extended release (ER) 4 mg, compared with placebo with regard to objective measures such as reduction in number of voids per 24 hours, mean volume per void, mean number of episodes of general urinary incontinence, urgency urinary incontinence and urgency per 24 hours; and subjective measures such as severity of urgency, patient perception of bladder condition and validated continence quality of life questionnaires. Regarding tolerability, these data would suggest that patients taking mirabegron suffer a similar rate of adverse effects as those taking placebo alone, whereas the rate in those taking antimuscarinics is greater. Thus mirabegron presents a safe and effective alternative treatment to antimuscarinics for patients with OAB symptoms. Patients who may particularly benefit from mirabegron include those who are unsuitable for antimuscarinics or who have previously struggled with antimuscarinic side effects.