Effects on sleep of anticholinergics used for overactive bladder treatment in healthy volunteers aged > or = 50 years

Oxybutynin-associated Cognitive Impairment: Evidence and Implications for Overactive Bladder Treatment

Anticholinergic medications have long been a mainstay of overactive bladder (OAB) treatment. Oxybutynin, a first-generation anticholinergic, still accounts for more than half of all OAB medication prescriptions, despite associations with impaired memory and cognition, as well as mounting evidence that it may increase the risk of incident dementia. This review details the current literature regarding oxybutynin and cognition, including evidence from preclinical, clinical, and real-world studies that show that oxybutynin binds nonspecifically to muscarinic receptors in the brain and is associated with adverse cognitive outcomes. We also discuss society recommendations to reduce use of oxybutynin and other anticholinergics to treat OAB.

Potential side effects of currently available pharmacotherapies in male lower urinary tract symptoms suggestive of benign prostatic hyperplasia

INTRODUCTION

The drug classes of α1-adrenoceptor antagonists, 5α-reductase inhibitors, and phosphodiesterase type 5 inhibitors are guideline-recommended treatments of lower urinary tract symptoms suggestive of benign prostatic hyperplasia; muscarinic receptor antagonists and β3-adrenoceptor agonists are also recommended if storage symptoms are insufficiently addressed with one of the other three drug classes.

AREAS COVERED

We provide a narrative review (no formalized literature searches performed) of the tolerability of these drug classes with emphasis on the more recently introduced medications, on combination treatment, and on more lately emerging risks.

EXPERT OPINION/COMMENTARY

The tolerability profiles are distinct between drug classes but, with few exceptions, similar within a drug class. Within a drug, formulations with longer duration of action tend to have better tolerability. Efficacy gains using combination treatment at least partly come at a cost of lesser tolerability. Greater susceptibility to experience adverse events based on age, comorbidities, and comedications appears conceptually important but remains under-investigated in this therapeutic area.

Diurnal effects of polypharmacy with high drug burden index on physical activities over 23 h differ with age and sex

Aging, polypharmacy (concurrent use of ≥ 5 medications), and functional impairment are global healthcare challenges. However, knowledge of the age/sex-specific effects of polypharmacy is limited, particularly on daily physical activities. Using continuous monitoring, we demonstrated how polypharmacy with high Drug Burden Index (DBI-cumulative anticholinergic/sedative exposure) affected behaviors over 23 h in male/female, young/old mice. For comparison, we also evaluated how different drug regimens (polypharmacy/monotherapy) influenced activities in young mice. We found that after 4 weeks of treatment, high DBI (HDBI) polypharmacy decreased exploration (reduced mean gait speed and climbing) during the habituation period, but increased it during other periods, particularly in old mice during the transition to inactivity. After HDBI polypharmacy, mean gait speed consistently decreased throughout the experiment. Some behavioral declines after HDBI were more marked in females than males, indicating treatment × sex interactions. Metoprolol and simvastatin monotherapies increased activities in young mice, compared to control/polypharmacy. These findings highlight that in mice, some polypharmacy-associated behavioral changes are greater in old age and females. The observed diurnal behavioral changes are analogous to drug-induced delirium and sundowning seen in older adults. Future mechanistic investigations are needed to further inform considerations of age, sex, and polypharmacy to optimize quality use of medicines.

The cognitive effect of anticholinergics for patients with overactive bladder

Overactive bladder (OAB) is often treated with medications that block the cholinergic receptors in the bladder (known as anticholinergics). The effect of this medication class on cognition and risk of dementia has been increasingly studied over the past 40 years after initial studies suggested that the anticholinergic medication class could affect memory. Short-term randomized clinical trials demonstrated that the administration of the anticholinergic oxybutynin leads to impaired memory and attention, and large, population-based studies showed associations between several different anticholinergic medications and dementia. However, trials involving anticholinergics other than oxybutynin have not shown such substantial effects on short-term cognitive function. This discordance in results between short-term cognitive safety of OAB anticholinergics and the long-term increased dementia risk could be explained by the high proportion of patients using oxybutynin in the OAB subgroups of the dementia studies, or a study duration that was too short in the prospective clinical trials on cognition with other OAB anticholinergics. Notably, all studies must be interpreted in the context of potential confounding factors, such as when prodromal urinary symptoms associated with the early stages of dementia lead to an increase in OAB medication use, rather than the use of OAB medication causing dementia. In patients with potential risk factors for cognitive impairment, the cautious use of selected OAB anticholinergic agents with favourable physicochemical and pharmacokinetic properties and clinical trial evidence of cognitive safety might be appropriate.

Choosing the Most Efficacious and Safe Oral Treatment for Idiopathic Overactive Bladder: A Systematic Review and Network Meta-analysis

CONTEXT

The choice of the most efficacious drug for patients with idiopathic overactive bladder (IOAB) remains challenging.

OBJECTIVE

The aim of this network meta-analysis was to determine the most efficacious oral antimuscarinic or β-adrenoceptor agonist accounting for adverse events for the management of IOAB.

EVIDENCE ACQUISITION

A comprehensive electronic search was done in MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, and Ovid for studies in any language in February 2021 considering the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. We included all randomized controlled trials assessing oral antimuscarinics or β-adrenoceptor agonists for the treatment of IOAB. We determined the effect of specific bothersome symptoms separately.

EVIDENCE SYNTHESIS

Fifty-four articles were included in our analysis. The most efficacious agents considering the evaluated outcomes were oxybutynin 15 mg/d in reducing incontinence episodes, imidafenacin 0.5 mg/d together with solifenacin 10 and 5 mg/d in reducing micturition episodes, fesoterodine 4 and 8 mg/d as well as solifenacin 10 mg/d in reducing urgency episodes, imidafenacin 0.5 mg/d and solifenacin 10 mg/d in reducing urgency urinary incontinence episodes, and solifenacin 10 mg/d, vibegron 50 mg/d, and fesoterodine 8 mg/d in improving the voided volume. Gastrointestinal problems, especially due to antimuscarinic agents, were the most prevalent adverse events.

CONCLUSIONS

Taken together, there is only minimal difference between the efficacy of oral antimuscarinics and that of β-adrenoceptor agonists. Although finding the best medication for all is impossible, finding the best treatment for every individual patient can be done by considering the efficacy of a medicine for the most bothersome symptom(s) in balance with drug-specific adverse events.

PATIENT SUMMARY

This study aimed to find the most efficient oral medication to treat overactive bladder, taking into consideration the adverse events. Based on our study, there is a minimal difference in the efficacy between the two major drug classes used to treat overactive bladder. Gastrointestinal problems were the most common adverse events in medical treatment of overactive bladder. Selection of the best treatment is possible through shared decision-making between the doctor and the patient based on the patient's most bothersome symptom. We provide a framework for physicians to facilitate shared decision-making with each individual patient.

Cognitive and mood side effects of lower urinary tract medication

Introduction: Muscarinic receptor antagonists, 5α-reductase inhibitors and α₁-adrenoceptor antagonists are frequently used drug classes for the treatment of lower urinary tract symptoms including those of overactive bladder syndrome and benign prostatic enlargement/benign prostatic obstruction. Areas covered: The authors review the evidence for adverse effects of these drug classes on cognitive function, mood and other functions of the central nervous system and discuss such effects against the evidence for mechanistic plausibility. Expert opinion: Muscarinic antagonists carry a risk for impaired cognition and other brain functions that differs quantitatively between compounds, being highest with oral formulations of oxybutynin. 5□-Reductase inhibitors can cause depressive symptoms even at low doses and starting several months after discontinuation of treatment. The evidence for α₁-adrenoceptor antagonists and specifically tamsulosin to cause dementia is controversial and lacks mechanistic plausibility. We recommend that physicians treating patients with lower urinary tract symptoms carefully monitor mental status prior to prescribing and periodically thereafter.

Effects of the P-Glycoprotein Inhibitor Clarithromycin on the Pharmacokinetics of Intravenous and Oral Trospium Chloride: A 4-Way Crossover Drug-Drug Interaction Study in Healthy Subjects

The quaternary ammonium compound trospium chloride is poorly absorbed from 2 "absorption windows" in the jejunum and cecum/ascending colon, respectively. To confirm whether intestinal P-glycoprotein (P-gp) is involved, a 4-period, crossover drug interaction study with trospium chloride after intravenous (2 mg) and oral administration (30 mg) without and after comedication of clarithromycin (500 mg), an inhibitor for P-gp, was initiated in 12 healthy subjects. Pharmacokinetics of trospium was evaluated using gas chromatography-mass spectrometry, noncompartmental evaluation, and pharmacokinetic modeling. Trospium chloride was poorly absorbed after oral administration (absolute bioavailability, ∼8%-10%). About 30% of the bioavailable dose fraction was absorbed from the "narrow window". Comedication with clarithromycin increased steady-state distribution volumes by ∼27% (P < .01). Bioavailability was not increased as hypothesized. The geometric mean ratios (90% confidence interval) for area under the plasma concentration-time curve, maximum concentration, and renal clearance accounted for 0.75 (0.56-1.01), 0.64 (0.45-0.89), and 1.00 (0.90-1.13), respectively. The amount of trospium absorbed from the "narrow window" was reduced in all subjects but from the "wider window" in only 9 of them. Bioavailability was strongly predicted by the maximum absorption rate of trospium in the distal "window" (rs²  = 0.910, P < .0001). In conclusion, the P-gp inhibitor clarithromycin significantly increases distribution volumes but not oral absorption of trospium. The amount absorbed from the "narrow window" was lowered in all subjects. However, the extent of all influences seems not to be of clinical relevance.

Anticholinergic burden and comorbidities in patients attending treatment with trospium chloride for overactive bladder in a real-life setting: results of a prospective non-interventional study

BACKGROUND

Elderly people are representative for the patients most likely to be treated with anticholinergics for overactive bladder (OAB). They often receive further drugs with anticholinergic properties for concomitant conditions. This increases the risk for side effects, including central nervous system disorders. Data on comorbidities and baseline anticholinergic burden of OAB patients seen in urological practice is scarce. Therefore, we included an epidemiological survey on these issues in our study which assessed the effectiveness and tolerability of trospium chloride (TC) in established dosages under routine conditions.

METHODS

Outpatients (≥ 65 years of age), for whom treatment with TC was indicated, were eligible to participate in this non-interventional, prospective study performed in 162 urological practices in Germany. Epidemiological questions were evaluated by the Anticholinergic Burden (ACB) scale and the Cumulative Illness Rating Scale for Geriatrics (CIRS-G) at baseline. Efficacy was assessed by changes in symptom-related variables of OAB after treatment. Dosage regimen, duration of treatment, adverse events, withdrawals, and ease of subdivision of the prescribed SNAP-TAB tablet were documented. Patients and physicians rated efficacy and tolerability of treatment. Statistics were descriptive.

RESULTS

Four hundred fourty-five out of 986 (47.54%) patients in the epidemiological population had a baseline ACB scale score > 0, 100 (24.72%) of whom a score ≥ 3. The median CIRS-G comorbidity index score for all patients was 5. 78.55% (608/774) of patients in the efficacy population received a daily dose of 45 mg TC. 60.03% (365/608) of them took this dose by dividing the SNAP-TAB tablet in three equal parts. Before-after-comparisons of the core symptoms of OAB showed clear improvements. An influence of the dosage scheme (1 × 45 mg TC/d vs 3 × 15 mg TC/d) on clinical outcome could not be observed. Most urologists and patients rated TC treatment as effective and well tolerated. 44 (4.37%) out of 1007 patients in the safety collective ended their treatment prematurely, while 75 patients (7.45%) experienced adverse events.

CONCLUSIONS

Anticholinergic burden and comorbidities in elderly OAB patients are frequent. The acceptance of the SNAP-TAB tablet, which facilitates flexible dosing with TC, was high, which is supportive in ensuring adherence in therapy.

TRIAL REGISTRATION

This non-interventional study was registered on October 29, 2014 with the number DRKS00007109 at the German Register of Clinical Studies (DRKS).

Treatment of Overactive Bladder in the Elderly Female: The Case for Trospium, Oxybutynin, Fesoterodine and Darifenacin

Overactive bladder (OAB) is a common constellation of lower urinary tract storage symptoms that causes a significant impact on a person's quality of life. The elderly may be disproportionally impacted by these symptoms due to concomitant poor mobility, comorbid conditions such as diabetes and heart failure, and polypharmacy. While behavioral modification and pelvic floor muscle training should be considered first-line treatment options, pharmacotherapy remains the backbone of the therapeutic regimen. Trospium, oxybutynin, fesoterodine, and darifenacin all have unique properties that may confer certain advantages in the elderly population. The hydrophilicity and quaternary amine structure of trospium may limit its ability to cross the blood-brain barrier and thus minimize impact on cognition in the elderly. In its oral form, oxybutynin may have the most significant effect on cognition; however, the transdermal preparations may be favorable in the elderly population due to the ability to avoid first-pass metabolism and its limited antimuscarinic adverse effects. Fesoterodine may be the most extensively studied OAB medication in the elderly population. Darifenacin has a strong affinity for the M3 receptor in the bladder, while having a weak affinity for the M1 receptor commonly found in the brain. It must be noted that all muscarinic receptor antagonists are associated with common adverse effects to some degree, and frequent re-evaluation of the elderly patient is necessary to confirm the proper benefit-to-risk profile.

Refractory overactive bladder: a common problem?

INTRODUCTION AND HYPOTHESIS

Unsatisfactory treatment outcome sometimes is described as frequently occurring in patients treated with first-line therapy for overactive bladder (OAB). The present article reviews the different circumstances which may result in failure to respond to lifestyle interventions, behavioral therapy, and/or antimuscarinic treatment.

METHODS

An extensive literature search was conducted to identify relevant articles on pathophysiological, clinical, and pharmacological aspects of refractory OAB.

RESULTS

Missing definition, unrealistic individual expectation of treatment outcomes, lack of communication between physician and patient as well as pathophysiological and pharmacological processes were identified as relevant for failure to respond to first-line OAB treatment. Increase of patient's motivation to adhere to the prescribed treatment, critical examination of the patient in regard to the initial diagnosis, and individual adjustment of antimuscarinic therapy may be appropriate tools to improve treatment outcome in OAB patients.

CONCLUSIONS

Overall, the incidence of refractory OAB seems to be overestimated. There are several approaches to improve therapy results.

Rationale for the use of anticholinergic agents in overactive bladder with regard to central nervous system and cardiovascular system side effects

PURPOSE

Central nervous system (CNS) and cardiovascular system (CVS) side effects of anticholinergic agents used to treat overactive bladder (OAB) are underreported. Hence, this review aimed to focus on the mechanisms of CNS and CVS side effects of anticholinergic drugs used in OAB treatment, which may help urologists in planning the rationale for OAB treatment.

MATERIALS AND METHODS

PubMed/MEDLINE was searched for the key words "OAB," "anticholinergics," "muscarinic receptor selectivity," "blood-brain barrier," "CNS," and "CVS side effects." Additional relevant literature was determined by examining the reference lists of articles identified through the search.

RESULTS

CNS and CVS side effects, pharmacodynamic and pharmacokinetic properties, the metabolism of these drugs, and the clinical implications for their use in OAB are presented and discussed in this review.

CONCLUSIONS

Trospium, 5-hydroxymethyl tolterodine, darifenacin, and solifenacin seem to have favorable pharmacodynamic and pharmacokinetic properties with regard to CNS side effects, whereas the pharmacodynamic features of darifenacin, solifenacin, and oxybutynin appear to have an advantage over the other anticholinergic agents (tolterodine, fesoterodine, propiverine, and trospium) with regard to CVS side effects. To determine the real-life situation, head-to-head studies focusing especially on CNS and CVS side effects of OAB anticholinergic agents are urgently needed.

Cognitive effects of oxybutynin chloride topical gel in older healthy subjects: a 1-week, randomized, double-blind, placebo- and active-controlled study

BACKGROUND AND OBJECTIVE

Oxybutynin is a common antimuscarinic therapy for overactive bladder. Transdermally administered oxybutynin chloride topical gel 10% (OTG) has a low propensity for anticholinergic adverse effects and possibly also a low risk of cognitive impairment. A randomized, double-blind, placebo- and active-controlled study evaluated the effects of OTG on cognitive and psychomotor functions in older healthy adults.

METHODS

Healthy adults aged 60-79 years were assigned randomly (1:1:1) to 1-week's treatment with OTG (1 g [100 mg oxybutynin] applied once daily on rotating sites of upper arms/shoulders, abdomen or thighs) plus oral placebo, immediate-release oxybutynin (OXB-IR; 5 mg capsule three times/day) plus placebo gel, or double placebo. Delayed recall Name-Face Association Test (NFAT) score was the primary end point. Treatments were compared by analysis of covariance.

RESULTS

Of 152 participants (mean age, 68 years), 49 received OTG, 52 OXB-IR and 51 placebo. NFAT Delayed Recall tests revealed no significant treatment differences (overall, p = 0.2733; OTG vs placebo, p = 0.1551; OXB-IR vs placebo, p = 0.1767). However, a significant effect (p = 0.0294) was noted for the Misplaced Objects Test, with scores declining only for OXB-IR. Approximately twice as many participants receiving OXB-IR (n = 10) as those receiving OTG (n = 5) or placebo (n = 6) showed a significant decline (≥6 points) in Total Recall score for the Hopkins Verbal Learning Test-Revised. No significant effects on psychomotor reaction time were observed. The most common adverse event, dry mouth, occurred in 6.1%, 73.1% and 7.8% of participants receiving OTG, OXB-IR and placebo, respectively.

CONCLUSIONS

OTG applied for 1 week had no clinically meaningful effect on recent memory or other cognitive functions in healthy, older adults.

CLINICAL TRIAL REGISTRATION

Registered as NCT00752141 at www.clinicaltrials.gov.

Effect of imidafenacin on nocturia and sleep disorder in patients with overactive bladder

OBJECTIVE

To evaluate the efficacy of imidafenacin on nocturia and sleep disorder in patients with overactive bladder (OAB).

PATIENTS AND METHODS

A prospective multicenter study of imidafenacin 0.1 mg twice daily for patients with OAB and nocturia was conducted. At baseline and at week 4 and 8, patients were assessed using the overactive bladder symptom score (OABSS), frequency volume charts (FVC) and the Pittsburgh Sleep Quality Index (PSQI).

RESULTS

Treatment with imidafenacin significantly improved OAB symptoms. Imidafenacin also improved PSQI, especially subjective sleep quality, sleep latency and daytime dysfunction. In FVC, the number of daytime voids and nighttime voids significantly decreased and average voided volume significantly increased after imidafenacin. Subanalysis of FVC based on the patients' age revealed that nocturnal polyuria was more often found in patients aged 75 years or over than in those aged under 75 years (79 vs. 55%, p < 0.05). Treatment with imidafenacin significantly reduced the nocturnal polyuria index only in patients aged 75 years or over.

CONCLUSIONS

Imidafenacin can improve nocturia and sleep disorder in patients with OAB. The efficacy of imidafenacin on nocturia is attributable to an increase in bladder capacity and a decrease in nocturnal urine volume. We conclude that imidafenacin is an effective and safe drug for nocturia in patients with OAB.

Antimuscarinic drugs: review of the cognitive impact when used to treat overactive bladder in elderly patients

The blockade of muscarinic receptors in the management of overactive bladder (OAB) symptoms provides beneficial as well as adverse effects. The cognitive changes observed are caused by the drugs' ability to cross the blood-brain barrier and bind to muscarinic receptors within the central nervous system (CNS). To date, while not specifically testing for CNS side effects, most of the controlled efficacy trials of multiple OAB medications have not shown significant adverse effects on cognitive function. However, elderly individuals, in whom OAB is more prevalent, often are excluded from these studies. The few trials that have performed cognitive testing in healthy elderly people taking antimuscarinics have clearly shown that oxybutynin can adversely affect cognition. Darifenacin, trospium, solifenacin, and tolterodine appear to have little to no risk of causing CNS side effects in this population. However, caution needs to be used in elderly patients with preexisting dementia.

A comprehensive non-clinical evaluation of the CNS penetration potential of antimuscarinic agents for the treatment of overactive bladder

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

This study provides antimuscarinic agents for overactive bladder (OAB) display variable association with side effects mediated by the central nervous system (CNS), which may be of particular concern in the elderly. Adverse effects on CNS functioning are related to muscarinic receptor subtype selectivity and the ability of the agent to cross the blood-brain barrier, where P-gp plays a role in limiting permeability.

WHAT THIS STUDY ADDS

This study provides a parallel investigation of CNS penetration of antimuscarinic OAB agents in vivo and assessment of physical properties and permeability in cell monolayers in vitro. It adds further understanding of the roles of passive transcellular permeability and P-gp in determining CNS penetration of antimuscarinic OAB agents. It also enables a comparison of CNS side-effect profiles of OAB agents with preclinical CNS penetration data.

AIMS

To assess and compare the mechanisms of central nervous system (CNS) penetration of antimuscarinic overactive bladder (OAB) agents.

METHODS

Physical properties were computed or compiled from the literature. Rats were administered 5-hydroxymethyl tolterodine (HMT), darifenacin, oxybutynin, solifenacin, tolterodine or trospium subcutaneously. At 1 h postdose, plasma, brain and cerebrospinal fluid (CSF) concentrations were determined using LC-MS/MS assays. Brain and plasma protein binding were determined in vitro. Permeability in the presence and absence of the efflux transporter P-glycoprotein (P-gp) was assessed in RRCK and MDCK-MDR1 transwell assays.

RESULTS

Oxybutynin displayed extensive CNS penetration, with brain:plasma ratios (B:P), unbound brain:unbound plasma ratios (Kp,free) and CSF:free plasma ratios each >1. Tolterodine (B:P = 2.95, Kp,free = 0.23 and CSF:free plasma = 0.16) and solifenacin (B:P = 3.04, Kp,free = 0.28 and CSF:free plasma = 1.41) showed significant CNS penetration but with some restriction from CNS as indicated by Kp,free values significantly <1. 5-HMT, darifenacin and trospium displayed much lower B:P (0.03-0.16), Kp,free (0.01-0.04) and CSF:free plasma (0.004-0.06), consistent with poor CNS penetration. Permeability in RRCK cells was low for trospium (0.63 × 10(-6) cm s(-1) ), moderate for 5-HMT (11.7 × 10(-6) cm s(-1) ) and high for darifenacin, solifenacin, tolterodine and oxybutynin (21.5-38.2 × 10(-6) cm s(-1) ). In MDCK-MDR1 cells 5-HMT, darifenacin and trospium, were P-gp substrates, whereas oxybutynin, solifenacin and tolterodine were not P-gp substrates.

CONCLUSIONS

Brain penetration was low for antimuscarinics that are P-gp substrates (5-HMT, darifenacin and trospium), and significant for those that are not P-gp substrates (oxybutynin, solifenacin and tolterodine). CNS adverse events reported in randomized controlled clinical trials show general alignment with the preclinical data described in this study.

Urinary Urgency Medications May Compromise Discrete rather than Global Cognitive Skills

BACKGROUND/AIMS

Prior research about cognitive problems associated with the use of urinary urgency medication (UUM) has reported mixed results that suggest procedures and/or assessments may need to be refined.

METHODS

Ten elderly subjects who were actively taking a UUM were assessed with neuropsychological testing before and after a 4-week UUM washout period. Results were evaluated by examining discrete subtest results, full-scale scores, and the reliable change index methodology.

RESULTS

Four controls and 5 subjects with mild cognitive impairment showed significant improvement in at least one subtest score on well-characterized instruments.

CONCLUSION

In this case study of 10 subjects, withdrawal of oxybutynin and tolterodine resulted in significant changes in subtest scores with different patterns for each subject that were not necessarily reflected in their total scores. Thus, future clinical studies should always include analysis of subtest results as these changes may be the only indication that cognition has been improved or has declined significantly.

Antimuscarinics for the treatment of overactive bladder: understanding the role of muscarinic subtype selectivity

INTRODUCTION AND HYPOTHESIS

Antimuscarinic agents appear to exert their therapeutic activity in overactive bladder (OAB) via blockade of the M(3) muscarinic receptor subtype. Antimuscarinics are broadly similar in efficacy, but their safety and tolerability profiles vary, which may reflect differences in muscarinic receptor selectivity profiles.

METHODS

This review of available literature aims to determine whether antimuscarinic agents with greater M(3) selectivity have clinical advantages over less selective drugs.

RESULTS

Antimuscarinic agents differ widely in their propensity to cause cognitive and cardiovascular (CV) effects, which appear mainly to be related to differences in their relative selectivity for binding to non-M(3) receptors, including M(1) receptors in the brain and cardiac M(2) receptors.

CONCLUSIONS

Cognitive and CV effects are especially pertinent for the OAB patient who tends to be older with various comorbidities and is often taking multiple medications. Hence, it is important to consider the risk/benefit balance of antimuscarinic agents when selecting OAB treatment.

Anticholinergics for overactive bladder therapy: central nervous system effects

The mainstay of pharmacological treatment of overactive bladder (OAB) is anticholinergic therapy using muscarinic receptor antagonists (tertiary or quaternary amines). Muscarinic receptors in the brain play an important role in cognitive function, and there is growing awareness that antimuscarinic OAB drugs may have adverse central nervous system (CNS) effects, ranging from headache to cognitive impairment and episodes of psychosis. This review discusses the physicochemical and pharmacokinetic properties of OAB antimuscarinics that affect their propensity to cause adverse CNS effects, as observed in phase III clinical trials and in specific investigations on cognitive function and sleep architecture. PubMed/MEDLINE was searched for "OAB" plus "muscarinic antagonists" or "anticholinergic drug." Additional relevant literature was identified by examining the reference lists of papers identified through the search. Preclinical and clinical trials in adults were assessed, focusing on the OAB antimuscarinics approved in the United States. The blood-brain barrier (BBB) plays a key role in protecting the CNS, but it is penetrable. The lipophilic tertiary amines, particularly oxybutynin, are more likely to cross the BBB than the hydrophilic quaternary amine trospium chloride, for which there are very few reports of adverse CNS effects. In fact, in 2008 the US product labels for oral oxybutynin were modified to include the potential for anticholinergic CNS events and a warning to monitor patients for adverse CNS effects. Even modest cognitive impairment in the elderly may negatively affect independence; therefore, selection of an antimuscarinic OAB drug with reduced potential for CNS effects is advisable.

The blood-brain barrier: geriatric relevance of a critical brain-body interface

The blood-brain barrier (BBB) represents the interface between the brain and other body tissues. Its ability to protect the brain from harmful compounds has attracted the attention of clinicians and investigators, but far from being a simple physical barrier, the BBB is a complex, heterogeneous, and dynamic tissue. The integrated function of the cerebral microvasculature, tight junction proteins, brain microvascular endothelial cells (BMECs), cellular transport pathways, and enzymatic machinery jointly contribute to normal BBB integrity. Aging, systemic diseases, and ischemic injury can disrupt these processes, resulting in a decline in overall BBB function and integrity. Based on the published literature, this study proposes that age- and disease-related BBB alterations play a key role in diminishing the ability of older patients to recover from acute ischemic stroke. Evidence linking deficits in the cerebral microvasculature and BBB integrity to dementia, medication-related cognitive decline, white matter disease (WMD or leukoaraiosis), and related geriatric syndromes including delirium, gait disorders, and urinary incontinence is also reviewed. Priority areas for a future research agenda include strategies to improve clinicians' ability to diagnose, prevent, and manage BBB abnormalities. In future years, in vivo measures such as functional and contrast-enhanced neuroimaging will be used to evaluate BBB integrity in older adults while also assessing the effectiveness of interventions, some targeting inflammatory pathways known to disrupt the BBB, for their ability to prevent or slow the progression of these complex multifactorial geriatric syndromes.

Trospium chloride has no effect on memory testing and is assay undetectable in the central nervous system of older patients with overactive bladder

BACKGROUND

Muscarinic receptors in the brain play an important role in cognitive function, especially memory, and there is growing awareness that specific antimuscarinic drugs for overactive bladder (OAB) may have adverse central nervous system (CNS) effects. Selection of an antimuscarinic OAB drug with reduced potential for CNS effects could be especially beneficial in the elderly people, in whom even the modest cognitive impairment may negatively affect independence.

PURPOSE

The purpose of the study is to determine if trospium chloride is assay detectable in the CNS of older adults with OAB and to assess whether deterioration of memory occurs in these individuals.

METHODS

Twelve cognitively intact older adults (>or=65-75 years old) with OAB were given extended-release trospium chloride 60 mg once daily over a 10-day period to achieve plasma steady-state levels. Standardised memory testing (Hopkins Verbal Learning Test-Revised and Brief Visuospatial Memory Test-Revised) was performed predose and postdose. Cerebrospinal spinal fluid (CSF) and plasma samples were drawn on day 10 and assayed for trospium chloride. Predose (day 0) and postdose (day 10) results on the memory tests were compared using a reliable change index to assess a meaningful change in learning or memory.

RESULTS

Trospium chloride levels in all the CSF samples (n = 72) of all participants were assay undetectable (<40 pg/ml) on day 10 at steady-state peak plasma concentration concurrent with measureable peak plasma values (C(max) = 925 pg/ml). Repeat memory testing revealed no significant net drug effect on learning or recall.

CONCLUSIONS

This is the first study to investigate for the presence of an OAB antimuscarinic in the human brain, performed by assaying for concentrations of trospium chloride and correlating with simultaneous clinical cognitive safety measures. The results of both pharmacological and neuropsychological testing support the hypothesis of a lack of detectable CNS penetration for the quaternary amine trospium chloride.

Review of cognitive impairment with antimuscarinic agents in elderly patients with overactive bladder

Overactive bladder (OAB) will become an increasingly prevalent problem as the proportion of older people in the population increases over the next 20 years. In addition to the urological symptoms (urinary urgency, with or without urgency incontinence, usually with increased daytime frequency and nocturia), OAB is associated with other problems in older patients, especially an increased risk of falls and fractures. The bother caused by OAB needs not be an inevitable consequence of ageing, because the symptoms can usually be alleviated, even in frail older people. Pharmacological treatment for OAB involves the use of antimuscarinic agents, whose efficacy and safety profiles depend on their interactions with muscarinic receptors that are widely distributed throughout the body. Interactions between antimuscarinics and M(1) receptors in the central nervous system may have the potential to cause cognitive impairment in older people, depending on muscarinic receptor binding profiles, lipophilicity and the ability to cross the blood brain barrier. Concerns over the possibility of cognitive impairment have contributed to an under-utilisation of antimuscarinics in the geriatric population, despite the high prevalence and severity of OAB in older subjects. Antimuscarinic agents should be actively considered for elderly patients with OAB, but it is desirable to establish the cognitive risk for every type of antimuscarinic, using robust cognition assessment methods.

Preserving cognitive function for patients with overactive bladder: evidence for a differential effect with darifenacin

BACKGROUND

Antimuscarinic agents used in the treatment of overactive bladder (OAB) differ in their potential to impair cognitive function. It is hypothesised that low brain concentrations and relatively low selectivity for the M(1) muscarinic receptor may reduce the potential for adverse central nervous system (CNS) effects with darifenacin, compared with other antimuscarinics, particularly oxybutynin.

METHODS

Cognitive function studies evaluating darifenacin, oxybutynin, tolterodine, solifenacin and/or trospium were identified from publications databases (Medline, Biosis and Embase) and congress abstracts. Preclinical studies and randomised controlled trials in adults were reviewed.

RESULTS

Five randomised, double-blind, multiple-dose studies of cognitive function were identified. Oxybutynin was consistently associated with cognitive deficit (four studies), whereas darifenacin did not impair cognition (three studies). These findings were supported by data from sleep/attention and EEG studies. Tolterodine data were limited to one small study with each formulation. For solifenacin and trospium, there were no human studies evaluating memory, the cognitive function most vulnerable to CNS anticholinergics.

CONCLUSIONS

There is compelling evidence of cognitive impairment with oxybutynin, whereas darifenacin stands out by demonstrating no impairment of memory or other cognitive functions in three randomised, controlled trials. This may be attributed to the differences in physicochemical properties, efflux mechanisms and relative M(1) muscarinic receptor sparing. The risk of CNS impairment is of particular concern for vulnerable populations such as the elderly (a substantial proportion of the OAB population), and CNS-compromised neurogenic bladder patients such as those with multiple sclerosis or Parkinson's disease.

In vivo quantitative autoradiographic analysis of brain muscarinic receptor occupancy by antimuscarinic agents for overactive bladder treatment

We evaluated the effects of five clinically used antimuscarinic agents for overactive bladder (OAB) treatment on in vivo muscarinic receptor binding in rat brain by quantitative autoradiography. There was a dose-related decrease in in vivo specific +N-[11C]methyl-3-piperidyl benzilate ([11C](+)3-MPB) binding in each brain region of rats 10 min after i.v. injection of oxybutynin, propiverine, solifenacin, and tolterodine. Rank order of the i.v. dose for 50% receptor occupancy (RO(50)) of antimuscarinic agents in rat brain regions was propiverine > solifenacin > tolterodine, oxybutynin. There was a good linear relationship between in vivo (pRO(50) values in the rat hippocampus) and in vitro (pK(i) values in human M(1) receptors) receptor binding activities of propiverine, solifenacin, and tolterodine. The observed RO(50) value of oxybutynin was approximately five times smaller than the predicted in vitro K(i) value. The dose ratios of antimuscarinic agents for the brain receptor occupancy (RO(50)) to the inhibition of carbachol- and volume-induced increases in intravesical pressure (ID(50)), which reflects in vivo selectivity for the urinary bladder over the brain, were greater for solifenacin, tolterodine, and propiverine than oxybutynin. Darifenacin displayed only a slight decrease in specific [11C](+)3-MPB binding in the rat brain regions, and it was not dose-related. In conclusion, in vivo quantitative autoradiographic analysis of brain muscarinic receptor occupancy may provide fundamental basis for managing central nervous system (CNS) side effects in antimuscarinic therapy for OAB. It is suggested that in the treatment of OAB, CNS side effects can be avoided by antimuscarinic agents with high selectivity for the urinary bladder over the brain.

Tolterodine does not affect memory assessed by passive-avoidance response test in mice

Antimuscarinics are first-line pharmacotherapy for the treatment of overactive bladder. However, because central nervous system cholinergic neurotransmission is involved in cognition, and the central nervous system-permeable antimuscarinics scopolamine and oxybutynin affect memory, cognitive impairment has been noted as a possible side effect of these drugs. We evaluated the effect of tolterodine, an antimuscarinic for overactive bladder, in a mouse passive-avoidance model of memory. Mice were chosen because like humans, mice but not rats, form the pharmacologically active 5-hydroxymethyl metabolite of tolterodine, DD01. In the passive-avoidance test, tolterodine at 1 or 3 mg/kg had no effect on memory; the latency to cross and percentage of animals crossing were comparable to controls. In contrast, scopolamine induced a memory deficit; the latency to cross was decreased, and the number of animals crossing was increased. Therefore, at a dose exceeding therapeutic exposure by six-fold, tolterodine had no effect on memory in the mouse passive-avoidance model, indicating that tolterodine does not disrupt cognitive function in this testing paradigm.

[How do medications used to treat urinary incontinence affect the cerebral function of the elderly?]

Anticholinergic agents are used for treatment of overactive bladder syndrome (OAB) by competitive blockade of acetylcholine at the muscarinic receptor. At present five different subtypes of M-receptors can be differentiated. Primary detrusor effects are mediated by M3-receptors as are side effects like dry mouth and constipation. Cardiac and central nervous system side effects appear to be M2 or M1 related. OAB symptom relief by the unselective drugs tolterodine, oxybutynin or trospium chloride and by M3-selective agents like darifenacin or solifenacin seems to be rather similar. Central side effects are different depending on gastrointestinal reabsorption, serum metabolism and penetration of the blood-brain barrier. Slow release formulations may be better tolerated. Anticholinergics that penetrate the blood-brain barrier may cause cognitive imbalance in older patients, as recent studies have shown for oxybutynin. Here M3-selective agents may offer an advantage.

New Options and Strategies for the Treatment of Urinary Incontinence

Urinary incontinence is a prevalent, although often unreported, disease within the elderly population, with consequences spanning many aspects of the patient's life. Treatments differ for each subtype of urinary incontinence: urge incontinence, stress incontinence, and incontinence associated with bladder outlet obstruction and lower urinary tract symptoms in men. Limitations in current therapies have negatively affected care for each of these subtypes, particularly in the vulnerable elderly population. An emergence of new treatment options and strategies has created opportunities to optimize care for the general population. These include the use of trospium, darifenacin, solifenacin, and duloxetine as well as the strategic use of antimuscarinic agents in conjunction with alpha adrenergic blockade in men with bladder outlet obstruction. Yet, the literature regarding use of these agents and strategies in the elderly should be carefully evaluated to determine the benefits and the unique risks posed by their use in this vulnerable population.

Trospium Chloride: Distinct Among Other Anticholinergic Agents Available for the Treatment of Overactive Bladder

Trospium chloride is an antimuscarinic agent indicated for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency, and urinary frequency. It has been available in Europe for over 20 years and in the United States since May 2004. Trospium has pharmacologic properties that are distinct from other antimuscarinic agents. The safety and efficacy profiles of trospium and how its pharmacologic properties contribute to these profiles form the basis for this review. The low incidence of adverse event of central nervous system effects and the efficacy parameters of "urgency" and "onset of action" are highlighted.

Darifenacin: Pharmacology and Clinical Usage

Darifenacin is one of several recently approved antimuscarinics for the treatment of overactive bladder (OAB) and urge urinary incontinence. Darifenacin is an effective drug for the treatment of OAB and is tolerated by patients. Darifenacin's M3 selectivity is unique among antimuscarinics. This M3 selectivity could confer advantages in patients who have cardiovascular side effects (tachycardia), impaired cognition, complaints of dizziness, or sleep disturbances. In some studies, darifenacin caused less dry mouth than oxybutynin. Rates of constipation, although significant, are tolerated and rarely a cause for discontinuation in clinical trials. This review describes the role of M3 receptors and covers the mechanism of action, pharmacokinetic properties, clinical efficacy safety and tolerability, drug interactions, and dosing guidelines for darifenacin.

The emergence of new drugs for overactive bladder

Overactive bladder is a common and distressing problem. Standard therapy is directed towards modifying the detrusor motor sensitivity and response via anticholinergic medication. Currently available medications are reviewed and alternative targets for treatment are presented.

Antimuscarinic drugs for overactive bladder and their potential effects on cognitive function in older patients

Antimuscarinic agents are the predominant pharmacological treatment for patients with overactive bladder (OAB). These drugs are thought to act primarily through antagonism at muscarinic M3 receptors located at neuromuscular junctions in the human bladder detrusor muscle. Several of these drugs have been shown to be efficacious in ameliorating the symptoms of OAB in older patients, but most currently available agents lack selectivity for the M3 receptor subtype, and interaction with other muscarinic receptor subtypes throughout the body may adversely affect a variety of physiological functions and result in unwanted side effects, including cognitive dysfunction. With the recent availability of antimuscarinic agents that show increased selectivity for M3 receptors relative to other muscarinic subtypes, an invitational expert panel meeting was convened to review not only the mechanisms by which antimuscarinic agents could affect cognitive function, but also the published literature on cognitive adverse events. A review of the literature shows that the cholinergic system in the central nervous system (CNS) exerts a major influence on cognitive processes, in particular memory via M1 cholinergic receptors. In addition, recent evidence suggests a role for M2 receptors in mediating cognitive function. Thus, cognitive dysfunction (including memory loss) during treatment with nonselective antimuscarinic agents for OAB is of growing concern, particularly in older patients and those with mild cognitive impairment or dementia. Increased blood-brain barrier permeability, which can occur with advanced age and certain comorbidities, may also facilitate CNS access of antimuscarinic agents (regardless of their physiochemical properties) and add to antimuscarinic burden. On the basis of available evidence, antimuscarinic agents with selectivity for M3 over M1 and M2 receptors, limited CNS penetration, or both may therefore offer a favorable balance of efficacy in treating OAB together with a reduced risk of adverse cognitive events in the older population.

Overactive Bladder in the Elderly

Overactive bladder (OAB) is a common condition characterised by the symptoms of urinary frequency and urgency, with or without urge incontinence and nocturia. The prevalence of OAB increases markedly with age in both men and women. OAB can have a detrimental effect on physical functioning and psychological well-being, as well as significantly reducing quality of life. Antimuscarinic therapy -- with or without behavioural therapy -- represents the most common treatment for patients with OAB. Several antimuscarinic agents are currently available for the treatment of OAB in adults, including oxybutynin, tolterodine, trospium chloride, darifenacin and solifenacin. The antimuscarinics all appear to exert their clinical effect through inhibition of the bladder muscarinic receptors, but they vary both in structure and in their functional profile. While efficacy has been demonstrated in adult populations (including patients >65 years of age), few studies have been reported specifically in a geriatric population, and antimuscarinics are often underutilised in the elderly despite the marked increase in the prevalence of OAB in this age group. One explanation for this apparent underuse of an effective treatment option may be concerns about the frequency of anticholinergic adverse events, such as dry mouth; the likelihood of detrimental CNS effects, including cognitive impairment and sleep disturbances; and the potential for harmful interactions with existing pharmacotherapy. When selecting an antimuscarinic agent for the management of an elderly patient presenting with OAB, in addition to considering evidence of clinical efficacy and tolerability, issues of safety specific to an older population should be borne in mind. In particular, the likelihood of detrimental CNS effects should be considered, including cognitive impairment and sleep disturbances, secondary to anticholinergic load. Oxybutynin and tolterodine have both been associated with cognitive adverse events and effects on sleep architecture and quality. In contrast, trospium chloride and darifenacin do not appear to be associated with cognitive adverse events and trospium chloride does not negatively affect sleep architecture or quality. Biotransformation by the cytochrome P450 (CYP450) system is an important step in the activation or elimination of a large number of drugs, including oxybutynin, tolterodine, darifenacin and solifenacin, raising the possibility of clinically relevant and potentially serious drug interactions. In elderly patients, such interactions are of particular relevance given the potential for declining activity of certain members of the CYP450 family combined with decreased hepatic blood flow, which can reduce first-pass metabolism and thus the bioavailability of drugs metabolised via this route. Of the antimuscarinic agents used to treat OAB, only trospium chloride is not extensively metabolised in the liver by the CYP450 system and is excreted largely as the active parent compound in the urine. This paper provides an overview of the pathophysiology of OAB and reviews current approaches to achieving a differential diagnosis and selecting appropriate treatment for the older patient. The pharmacology and clinical effects of current medication for the treatment of OAB symptoms in patients defined by the OAB pharmacology literature as 'elderly' are also reviewed.