Randomised, double-blind study of the effects of oxybutynin, tolterodine, trospium chloride and placebo on sleep in healthy young volunteers

SUFU white paper on overactive bladder anticholinergic medications and dementia risk

AIMS

Anticholinergic medications are widely used in the treatment of overactive bladder (OAB), as well as for short-term treatment of bladder symptoms following a variety of urologic surgeries. Mounting evidence points to an association between anticholinergic medications and the increased risk of incident dementia. The Society for Urodynamics, Female Pelvic Medicine, and Urogenital Reconstruction (SUFU) thus convened a committee of subject experts to contextualize the current understanding of the cognitive risks of anticholinergic medications in the urologic patient population and to provide practical clinical guidance on this subject.

METHODS

Statements are based on an expert literature review and the committee's opinion. The document has been reviewed and approved by the SUFU board.

RESULTS

Chronic use (>3 months) of OAB anticholinergic medications is likely associated with an increased risk of new-onset dementia. Short-term (<4 weeks) use of most OAB anticholinergic medications is likely safe in most individuals. Clinicians should consider potential cognitive risks in all patient populations when prescribing OAB anticholinergics for chronic use. Consideration should be given to progressing to advanced therapy (botulinum toxin or neuromodulation) earlier in the OAB treatment paradigm CONCLUSIONS: The current body of literature supports a likely small but significant increased risk of dementia with chronic exposure to OAB anticholinergic medications. Potential harms should be balanced against potential quality of life improvement with treatment.

The role of sex, age and genetic polymorphisms of CYP enzymes on the pharmacokinetics of anticholinergic drugs

There is evidence that use of drugs with anticholinergic properties increases the risk of cognitive impairment, and increased exposure to these drugs potentiates this risk. Anticholinergic drugs are commonly used even with associated risk of adverse events. Aging, sex, and genetic polymorphisms of cytochrome P450 (CYP) enzymes are associated with alterations in pharmacokinetic processes, which increase drug exposure and may further increase the risk of adverse drug events. Due to the increasing burden of cognitive impairment in our aging population and the future of personalized medicine, the objective of this review was to provide a critical clinical perspective on age, sex, and CYP genetic polymorphisms and their role in the metabolism and exposure to anticholinergic drugs. Age-related changes that may increase anticholinergic drug exposure include pseudocapillarization of liver sinusoidal endothelial cells, an approximate 3.5% decline in CYP content for each decade of life, and a reduction in kidney function. Sex-related differences that may be influenced by anticholinergic drug exposure include women having delayed gastric and colonic emptying, higher gastric pH, reduced catechol-O-methyl transferase activity, reduced glucuronidation, and reduced renal clearance and men having larger stomachs which may affect medication absorption. The overlay of poor metabolism phenotypes for CYP2D6 and CYP2C19 may further modify anticholinergic drug exposure in a significant proportion of the population. These factors help explain findings of clinical trials that show older adults and specifically older women achieve higher plasma concentrations of anticholinergic drugs and that poor metabolizers of CYP2D6 experience increased drug exposure. Despite this knowledge neither age, sex nor CYP phenotype are routinely considered when making decisions about the use or dosing of anticholinergic medications. Future study of anticholinergic medication needs to account for age, sex and CYP polymorphisms so that we may better approach personalized medicine for optimal outcomes and avoidance of medication-related cognitive impairment.

Different antimuscarinics when combined with atomoxetine have differential effects on obstructive sleep apnea severity

The combination of the noradrenergic agent atomoxetine plus the antimuscarinic oxybutynin has recently been shown to improve upper airway physiology and reduce obstructive sleep apnea (OSA) severity. However, the effects of different antimuscarinics when combined with atomoxetine is limited. This study aimed to determine the effects of atomoxetine combined with two different antimuscarinics with varying M-subtype receptor selectivity on OSA severity and upper airway physiology. Ten people with predominantly severe OSA completed a double-blind, randomized, placebo-controlled, cross-over trial. Participants completed three overnight in-laboratory sleep studies after either 80 mg atomoxetine + 5 mg solifenacin succinate (ato-sol) or 80 mg atomoxetine + 2 mg biperiden hydrochloride (ato-bip) or placebo. OSA severity, ventilatory stability (loop gain), respiratory-arousal threshold (via epiglottic manometry), next-day subjective sleepiness [Karolinska Sleepiness Scale (KSS)], and alertness were compared between conditions. Neither drug combination altered the apnea/hypopnea index versus placebo (P = 0.63). Ato-sol caused a shift toward milder respiratory events with reduced frequency of obstructive apneas (13 ± 14 vs. 22 ± 17 events/h; means ± SD, P = 0.04) and increased hypopneas during nonrapid eye movement (NREM) (38 ± 21 vs. 24 ± 18 events/h, P = 0.006) with improved nadir oxygenation versus placebo (83 ± 4 vs. 80 ± 8%, P = 0.03). Both combinations reduced loop gain by ∼10% versus placebo; sleep efficiency and arousal threshold were unaltered. Ato-bip reduced next-day sleepiness versus placebo (KSS = 4.3 ± 2.2 vs. 5.6 ± 1.6, P = 0.03). Atomoxetine + biperiden hydrochloride reduces perceived sleepiness, and atomoxetine + solifenacin modestly improves upper airway function in people with OSA but to a lesser extent versus recently published atomoxetine + oxybutynin (broad M-subtype receptor selectivity) findings. These results provide novel mechanistic insight into the role of noradrenergic and antimuscarinic agents on sleep and breathing and are important for pharmacotherapy development for OSA.NEW & NOTEWORTHY In contrast to recent findings of major reductions in OSA severity when atomoxetine is combined with a nonspecific antimuscarinic, oxybutynin (broad M-subtype receptor selectivity), addition of solifenacin succinate (M2 and M3 muscarinic receptor selectivity) or biperiden (M1 muscarinic receptor selectivity) with atomoxetine had modest effects on upper airway function during sleep, which provide mechanistic insight into the role of noradrenergic and antimuscarinic agents on sleep and breathing and are important for pharmacotherapy development for OSA.

A Multimethod, Case-Controlled Study of Sleep-Wake Disturbances in Adolescents With Spina Bifida

Objective

This study aimed to compare sleep-wake disturbances in adolescents with spina bifida (SB) to typically developing (TD) peers. Exploratory analyses examined sex as moderator of disrupted sleep.

Methods

Adolescents with SB (ages 12-18 years; N = 37) and a demographically matched sample of TD adolescents (N = 37) completed validated sleep questionnaires and underwent 10 days of actigraphy monitoring.

Results

Adolescents with SB evidenced worse sleep quality, shorter sleep duration, greater sleep maintenance difficulties, and higher levels of fatigue compared with their TD peers. Exploratory analyses revealed females with SB were particularly vulnerable to developing sleep disturbances.

Conclusions

Adolescents with SB are at risk for nighttime sleep disturbances and daytime fatigue. Additional research will need to identify mechanisms and adverse consequences of poor sleep to develop interventions addressing sleep deficiency. Sex-specific disparities in sleep patterns in pediatric SB is a novel finding that requires assessment of etiological underpinnings to clarify clinical implications.

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).

Oral Pharmacologic Management of Overactive Bladder Syndrome: Where Do We Stand?

Overactive bladder syndrome (OAB) is a prevalent disorder with a significant impact on quality of life. Despite this high prevalence, there is significant underdiagnosis and undertreatment due to several barriers, including embarrassment, poor communication and low patient adherence. Currently, various antimuscarinic are available in the treatment of OAB. The introduction of mirabegron has broadened the therapeutic approach and combination therapy of both agents can be valuable in clinical practice. Yet, patient adherence to most drugs for OAB is still relatively poor. Healthcare providers need to identify and utilise strategies to improve treatment adherence by defining clear treatment goals, implement educational methods and frequently communicate with patients to identify problems with adherence. The elderly population form need special attention as in these patients, anticholinergics should be prescribed with care and adequate knowledge regarding pharmacokinetics and drug interactions in essential. Furthermore, patient expectations should be clearly discussed. In this narrative review, the current advances in oral pharmacotherapy are evaluated and the most important factors involved in the management of OAB are discussed.

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.

Oxybutynin: past, present, and future

Oxybutynin chloride is primarily indicated for the treatment of overactive bladder syndrome (OAB). It remains the most widely prescribed compound for OAB in the world. OAB is defined as the presence of urinary urgency, usually accompanied by daytime urinary frequency and nocturia, with or without urgency urinary incontinence, in the absence of infection or other identifiable etiology. This is a significant problem for men and women said to affect over 33 million adults in the USA, with the prevalence increasing with age. These symptoms can alter quality of life, with both physical and psychological impairment, as well as cause significant financial burden including the cost of sanitary supplies and decreased work productivity. Both pharmacological and non-pharmacological methods may be employed to aid in the treatment of OAB. The mainstay of treatment for OAB relies on pharmacological management, most specifically treatment with antimuscarinic medications. These medications are thought to prevent involuntary bladder contractions and/or urgency by inhibiting the muscarinic receptors within the urothelium and detrusor muscle. Currently, there are six different medications approved by the US Food and Drug Administration (FDA) for the treatment of OAB, with more than nine formulations including immediate- and extended-release tablets, transdermal patch and gel, vaginal ring, and suppository. This review will focus specifically on oxybutynin chloride, which has been used to treat OAB for four decades in numerous formulations.

Pharmacokinetics and toxicity of antimuscarinic drugs for overactive bladder treatment in females

INTRODUCTION

Antimuscarinics (AMs) are the mainstay of pharmacological treatment of overactive bladder (OAB), a symptom complex defined by the presence of urinary urgency, usually associated with frequency and nocturia, with or without urgency urinary incontinence. The AMs used to treat OAB differ in their pharmacological profiles, which may affect their potential for causing adverse effects (AEs).

AREAS COVERED

The present article aims to review the literature about pharmacokinetics (PK) of the different AMs used in the treatment of OAB. Furthermore, the AEs related to the use of these drugs and their incidence are presented. This systematic review is based on material searched and obtained via Medline, Pubmed and EMBASE up to March 2012 using the search terms "adverse events, pharmacokinetics, tolerability" in combination with "darifenacin, fesoterodine, imidafenacin, oxybutynin, propiverine, solifenacin, tolterodine, and trospium."

EXPERT OPINION

Antimuscarinics are the first-line pharmacological treatment for OAB. Despite the development of new molecules that improve their efficacy/safety profile, there are some drugs that are pharmacokinetically more appropriate to be prescribed in specific populations such as patients with neurological disease or the elderly. Moreover, research should be encouraged in evaluating antimuscarinics in conjunction with other drugs such as estrogens or beta-agonists. The identification of prognostic criteria for pharmacological therapy would be helpful.

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.

Oxybutynin and trospium are substrates of the human organic cation transporters

The muscarinic antagonists oxybutynin and trospium are used as spasmolytic agents for the treatment of overactive urinary bladder disease. Recently, it has been shown that trospium, but not oxybutynin, is a substrate of the multidrug efflux carrier P-glycoprotein, but carrier-mediated drug uptake has not been directly analysed for both drugs. However, trospium has been previously shown to exhibit inhibitory potency for the organic cation transporters (OCTs). The aim of the present study was to examine whether trospium and oxybutynin are substrates, i.e. are transported by the human OCTs (hOCT(1), hOCT(2) and hOCT(3)). Therefore, we measured total and specific (decynium-22-sensitive) uptake, and saturation kinetics of the uptake for [(3)H]oxybutynin and [(3)H]trospium in human embryonic kidney (HEK293) cells transiently transfected with the cDNA of hOCT(1), hOCT(2) or hOCT(3). In addition, we determined IC(50) values for inhibition of hOCT-mediated [(3)H]MPP(+) uptake by unlabelled trospium and oxybutynin. Total uptake of [(3)H]oxybutynin was very high in all transfected HEK293 cells and only a small portion was due to specific, decynium-22-sensitive hOCT-mediated uptake. Oxybutynin inhibited [(3)H]MPP(+) uptake by the three hOCTs with IC(50) values between 20 and 130 μM. Direct determination of transport kinetics was measurable only at hOCT(1) with K (m) of 8 μM and V (max) of 484 pmol/mg protein/min. The rank order of affinity (1/IC(50) or 1/K (m)) of specific oxybutynin uptake was hOCT(1) > hOCT(2) = hOCT(3). The observed high non-specific uptake is obviously a consequence of the high lipophilicity of this uncharged drug. Thus, hOCTs may not play a significant role for the overall pharmacokinetics and tissue distribution of oxybutynin. However, and in contrast to oxybutynin, uptake of [(3)H]trospium, an organic cation, was mainly due to carrier-mediated uptake by the three hOCTs. With IC(50) values of 18, 1.4 and 710 μM (at hOCT(1), hOCT(2) and hOCT(3), respectively) and K (m) values of 17 and 8 μM and about identical V (max) values of about 90 pmol/mg protein/min at hOCT(1) and hOCT(2), respectively; the rank order of affinity (1/IC(50) or 1/K (m)) of specific uptake of trospium was hOCT(2) > hOCT(1) > > hOCT(3). Thus, hOCTs very probably contribute to the active tubular and hepatobiliary secretion of trospium. Furthermore, hOCT(1) and hOCT(3) may be involved in the tissue uptake of this drug in the urinary bladder.

Correlation between Nocturia and Sleep: A Questionnaire Based Analysis

Purpose

This study evaluated the effectiveness and quality of sleep (QoS) in adult patients with nocturnal lower urinary tract symptoms (LUTS) including nocturia and nocturnal polyuria.

Materials and Methods

A total of 102 patients with nocturia and daytime LUTS were enrolled in this study. All patients completed a questionnaire that included the International Prostate Symptom Score (IPSS), quality of life score (QoL), overactive bladder questionnaire (OABq), and a sleepiness index. The sleepiness index was measured with the Korean Beck Depression Inventory (K-BDI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), Berlin Questionnaire (BQ), and the International Restless Legs Syndrome Study Group (IRLSSG). Statistical analyses included the Student's t-test and chi-square test. Differences were considered significant at a p-value of less than 0.05.

Results

Nocturia during sleep was experienced by 68 (66.7%) out of 102 patients. There was no significant association between the nocturia- and the sleep-related scales, but with multiple regression analysis for sex and age, the K-BDI score (p=0.05), IPSS score (p=0.05), and OABq (p=0.02) were significantly higher in patients who woke up to void during sleep. A total of 57 (55.9%) patients diagnosed with overactive bladder with nocturia had severe daytime sleepiness on the ESS questionnaire (p=0.019) and more urgency symptoms on the IPSS questionnaire (p=0.007).

Conclusions

Patients with nocturia had a greater risk of being depressive and felt sleepier during the daytime. LUTS including nocturia and sleep quality closely affected each other. Therefore, clinicians should consider patients' LUTS and sleep problems or QoS as well to provide more satisfying outcomes.

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.

Trospium chloride treatment of overactive bladder

OBJECTIVE

To review the pharmacology, pharmacokinetics, safety, and clinical application of trospium chloride for the management of overactive bladder (OAB).

DATA SOURCES

Clinical literature including both primary sources and review articles was accessed through MEDLINE, International Pharmaceutical Abstracts, and Cochrane databases from 1980 through January 8, 2009. Search terms included overactive bladder, urge urinary incontinence, muscarinic receptor antagonists, and urinary frequency. Further data sources were identified from bibliographies of selected articles.

STUDY SELECTION AND DATA EXTRACTION

Basic pharmacology data were extracted from animal studies and pharmacokinetic data were gathered from human studies. Multicenter, parallel, randomized, double-blind, placebo-controlled studies were included to describe the efficacy and adverse effects of trospium.

DATA SYNTHESIS

Trospium chloride is an antimuscarinic agent indicated for the treatment of OAB with symptoms of urge urinary incontinence, urgency, and urinary frequency. Trospium has 3 chemical and pharmacokinetic properties unique among antimuscarinic agents: it is a positively charged quaternary ammonium compound with minimal central nervous system penetration; it is not metabolized by the cytochrome P450 system, resulting in a lower tendency for drug interactions; and it is excreted mainly unchanged in the urine as the active parent compound, providing local activity to achieve early onset of clinical effect and prolonged efficacy. In two 12-week, randomized, placebo-controlled clinical studies in adults with OAB, trospium 20 mg twice daily was more effective than placebo in reducing the number of micturitions per 24 hours, reducing the number of urge incontinence episodes per week, and increasing the volume of urine voided per micturition. Placebo-controlled trials report efficacy with trospium in treatment of OAB; comparative trials with other anticholinergic agents are limited. Current therapy of OAB consists primarily of anticholinergic drugs such as oxybutynin, which are associated with therapy-limiting adverse effects. Because the prevalence of OAB is greatest among the elderly, safety considerations regarding renal function must be noted, with dosage adjustment required in patients with severe renal impairment.

CONCLUSIONS

Whether the pharmacodynamic properties of trospium make it superior to other therapies will require considerable additional experience with the drug. For now, it appears to be a feasible alternative for patients who cannot tolerate oxybutynin.

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.

Antimuscarinics for the treatment of overactive bladder: a review of central nervous system effects

Antimuscarinic drugs commonly used to treat overactive bladder are often associated with central nervous system (CNS) side effects including cognitive dysfunction, memory impairment, dizziness, fatigue, and headache. New agents show reduced CNS penetrance and better selectivity for the M3 muscarinic receptor. However, changes associated with aging may lead to alterations in blood-brain barrier permeability. Therefore, use of antimuscarinics in the elderly or in patients with Alzheimer's disease presents a significant challenge. This review highlights muscarinic receptor distribution and function in the CNS, provides a description and incidence of CNS side effects with therapy, offers information specific to currently available agents, and describes the use of antimuscarinics in special populations including children, the elderly, and patients with Alzheimer's disease.

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.

Trospium chloride: the European experience

The primary pharmacological therapy for overactive bladder syndrome is muscarinic receptor antagonists. Muscarinic receptor blockade is effective in decreasing the symptoms of urinary urgency and urgency incontinence, but can be associated with troublesome complications, such as dry mouth, blurred vision, constipation and CNS side effects. Trospium chloride, an antimuscarinic medication, has been available in Europe for > 20 years and has recently been approved by the FDA for the treatment of overactive bladder. Trospium chloride is a quaternary amine that is minimally metabolised, not highly protein bound and, importantly, has not been demonstrated to cross the unaltered blood-brain barrier in healthy volunteers. Some characteristics of this unique antimuscarinic agent and the European experience with trospium chloride are reviewed in this article.

Muscarinic receptors: their distribution and function in body systems, and the implications for treating overactive bladder

1. The effectiveness of antimuscarinic agents in the treatment of the overactive bladder (OAB) syndrome is thought to arise through blockade of bladder muscarinic receptors located on detrusor smooth muscle cells, as well as on nondetrusor structures. 2. Muscarinic M3 receptors are primarily responsible for detrusor contraction. Limited evidence exists to suggest that M2 receptors may have a role in mediating indirect contractions and/or inhibition of detrusor relaxation. In addition, there is evidence that muscarinic receptors located in the urothelium/suburothelium and on afferent nerves may contribute to the pathophysiology of OAB. Blockade of these receptors may also contribute to the clinical efficacy of antimuscarinic agents. 3. Although the role of muscarinic receptors in the bladder, other than M3 receptors, remains unclear, their role in other body systems is becoming increasingly well established, with emerging evidence supporting a wide range of diverse functions. Blockade of these functions by muscarinic receptor antagonists can lead to similarly diverse adverse effects associated with antimuscarinic treatment, with the range of effects observed varying according to the different receptor subtypes affected. 4. This review explores the evolving understanding of muscarinic receptor functions throughout the body, with particular focus on the bladder, gastrointestinal tract, eye, heart, brain and salivary glands, and the implications for drugs used to treat OAB. The key factors that might determine the ideal antimuscarinic drug for treatment of OAB are also discussed. Further research is needed to show whether the M3 selective receptor antagonists have any advantage over less selective drugs, in leading to fewer adverse events.

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.

Pharmacodynamic effects of darifenacin, a muscarinic M3 selective receptor antagonist for the treatment of overactive bladder, in healthy volunteers

OBJECTIVE

To evaluate the pharmacodynamic effects of darifenacin (a muscarinic M(3) selective receptor antagonist) and dicyclomine (an M(1) selective receptor antagonist) in healthy male volunteers.

SUBJECTS AND METHODS

In this double-blind, four-way crossover study, 27 healthy men (aged 19-44 years) were randomized to receive darifenacin 7.5 mg or 15 mg once daily, dicyclomine 20 mg four times daily or matching placebo. Each 7-day treatment period was separated by a 7-day washout. Multiple assessments of cognitive function, quantitative electroencephalogram (EEG) recordings, salivation, visual nearpoint, heart rate and heart rate variability were made on day 7 in each treatment period.

RESULTS

Compared with placebo, neither dose of darifenacin affected cognitive function, whereas dicyclomine impaired performance on five of the 12 variables 2 h after dosing; simple reaction time (P = 0.009), speed of numeric (P = 0.012) and spatial (P = 0.048) working memory, and speed (P = 0.04) and sensitivity (P = 0.03) of picture recognition. These cognitive changes were accompanied by slowing of the EEG for dicyclomine. Darifenacin showed no clinically relevant effect on EEG. Darifenacin 7.5 and 15 mg once daily did not differ from placebo in effects on visual nearpoint, heart rate or heart rate variability. By contrast, dicyclomine significantly increased the maximum visual nearpoint, decreased heart rate and increased heart rate variability, relative to placebo. Both agents decreased salivary flow rate vs placebo. Treatment-related adverse events were comparable in all groups, the most common being dry mouth; none led to treatment discontinuation.

CONCLUSIONS

Darifenacin did not affect cognitive, cardiac or visual function in healthy volunteers, a profile that may reflect its relative M(3) receptor selectivity and M(1)/M(2) sparing properties.

Extended-release formulations of oxybutynin and tolterodine exhibit similar central nervous system tolerability profiles: a subanalysis of data from the OPERA trial

OBJECTIVE

This study was undertaken to compare the central nervous system (CNS) tolerability profiles of the extended-release formulations of oxybutynin chloride and tolterodine tartrate in the treatment of women with overactive bladder (OAB), as observed in the OPERA (Overactive bladder: Performance of Extended Release Agents) trial.

STUDY DESIGN

The OPERA trial was a randomized, double-blind, active-control comparison of the efficacy and safety of extended-release oxybutynin (10 mg/d) and extended-release tolterodine (4 mg/d) given to 790 women with OAB for 12 weeks. The incidence of reported CNS events was compared between the treatment groups by using the Fisher exact test.

RESULTS

The incidence of CNS adverse events was 9% and 8% for the oxybutynin and tolterodine treatment groups, respectively. The difference between groups was not statistically significant. All reported CNS adverse events were rated as mild or moderate in severity. There were no serious treatment-related adverse events in either group, and discontinuation because of a CNS adverse event was infrequent.

CONCLUSION

The extended-release formulations of oxybutynin and tolterodine were observed to be associated with a similar low incidence of CNS adverse events, which were mostly mild or moderate in severity.

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

OBJECTIVE

To study the influence of oxybutynin, tolterodine or trospium chloride, anticholinergics used to treat bladder overactivity, on sleep and the cognitive skills of healthy volunteers aged > or = 50 years.

SUBJECTS AND METHODS

In a randomized, double-blind, placebo-controlled study with a crossover design, 24 healthy sleepers (12 men and 12 women) aged 51-65 years underwent polysomnographic recordings and cognitive tests in a sleep laboratory. Study medications were given as a single dose containing the total recommended daily dose.

RESULTS

There was a significant reduction in rapid-eye movement (REM) sleep of approximately 15% and a slightly (but not significantly) greater REM latency after oxybutynin and tolterodine than with placebo. After trospium chloride, REM duration and latency were comparable with placebo. There was no effect of the tested anticholinergics on cognitive and subjective sleep variables.

CONCLUSION

Individuals aged > or = 50 years had a more distinct impairment of REM sleep after oxybutynin and tolterodine than had young people, but the reduction in REM sleep did not reach a pathological degree in this single-dose study. There was no apparent impairment of concentration or cognitive function, but impairment of cognitive function and neuropsychological side-effects cannot be excluded, especially when elderly patients with impaired REM sleep from various psychiatric diseases (e.g. depression) and/or sleep disturbances are given oxybutynin or tolterodine in long-term treatment.

Confusion about measuring central nervous system effects

Anticholinergic therapy together with behavioral treatment are the main stays of treatment for the overactive bladder. Successful therapy and patient compliance depend very much on side effects. In the past, little attention has been paid to anticholinergic side effects in the central nervous system (CNS), which can be critical, especially for elderly patients. Incidence and intensity of CNS effects depend on the pharmacokinetic and pharmacodynamic properties that are decisive whether anticholinergics pass the blood-brain barrier as a result of passive and active transport mechanisms. To measure potential CNS side effects of anticholinergic drugs, rapid eye movement sleep analysis, quantitative-topographic electroencephalogram studies, and psychometric tests were performed. Structural changes in brain morphology resulting from anticholinergics also were analyzed in a post-mortem study.

Trospium chloride in the management of overactive bladder

Trospium chloride is an orally active, quaternary ammonium compound with antimuscarinic activity. It binds specifically and with high affinity to muscarinic receptors M(1), M(2) and M(3), but not nicotinic, cholinergic receptors. It is hydrophilic and does not cross the normal blood-brain barrier in significant amounts and, therefore, has minimal central anticholinergic activity. Peak plasma trospium chloride concentrations are attained approximately 5-6 hours after oral administration, which should occur before meals as concurrent food ingestion significantly reduces trospium bioavailability. Trospium chloride undergoes negligible metabolism by the hepatic cytochrome P450 system; few metabolic drug interactions are known. While trospium chloride dosage adjustments based on age or sex appear unwarranted, such adjustments may be needed in patients with severe renal impairment. Direct comparative studies in patients with overactive bladder indicate that trospium chloride is at least as effective as oxybutynin and tolterodine. Placebo-controlled studies have also confirmed the efficacy of trospium chloride in terms of improved urodynamic parameters; small-scale, noncomparative studies have documented significant trospium chloride-induced improvements in patients with reflex neurogenic bladder, postoperative bladder irritation and radiation-induced cystitis; and observational studies including >10,000 patients have also revealed favourable findings for trospium chloride, including a marked decrease in incontinence episodes and substantial improvement in health-related quality of life. Trospium chloride is generally well tolerated, and significantly more so than immediate-release oxybutynin. The most frequent adverse events, occurring in >1% of trospium chloride-treated patients, are dry mouth, dyspepsia, constipation, abdominal pain and nausea. Available for many years in several countries outside North America, trospium chloride is likely to develop an important role in the management of overactive bladder following its approval in the US on 28 May 2004.

Antimuscarinic agents: Implications and concerns in themanagement of overactive bladder in the elderly

BACKGROUND

Overactive bladder (OAB) is a widespread problem that has a negative effect on quality of life, particularly among the elderly. Antimuscarinic agents are the only drug class with broad, accepted efficacy in the treatment of OAB. Their clinical usefulness, however, is limited by dose-dependent adverse effects. In the elderly, the most serious of these is central nervous system (CNS) dysfunction, including cognitive impairment.

OBJECTIVE

This article examines currently available antimuscarinic agents for the treatment of OAB in terms of their likelihood of causing CNS dysfunction by crossing the blood-brain barrier (BBB) and blocking muscarinic type 1 (Ml) receptor sites in the brain.

METHODS

Pertinent studies were selected from a comprehensive review of the OAB literature with a focus on muscarinic receptor-associated mechanisms leading to CNS adverse effects and their potential impact on elderly patients. MEDLINE was searched for articles published in the past 10 years, and additional articles were obtained from the reference lists of identified publications. Also searched were abstracts of recent meetings of the International Consultation on Incontinence, International Continence Society, American Urological Association, and European Association of Urology.

RESULTS

Antimuscarinic agents control involuntary detrusor muscle contractions through cholinergic blockade at the muscarinic receptors. The prevalence of OAB is highest in the elderly, the population most likely to be taking multiple anticholinergic medications and most vulnerable to the CNS adverse effects of these agents. Nonselective antimuscarinic agents that bind to the Ml receptor are most likely to cause significant cognitive adverse effects compared with the more selective antimuscarinic agents for the treatment of OAB.

CONCLUSIONS

When considering use of an antimuscarinic agent for the treatment of OAB in elderly patients, prescribers should routinely consider the agent's receptor selectivity and ability to cross the BBB. The medical history should include all current medications that may contribute to the anticholinergic burden and cognitive impairment. Patients and caregivers should be educated to recognize anticholinergic adverse effects.

TROSPIUM CHLORIDE IMPROVES OVERACTIVE BLADDER SYMPTOMS: A MULTICENTER PHASE III TRIAL

PURPOSE

Trospium chloride is an anticholinergic agent with predominantly peripheral nonselective antimuscarinic activity lacking central nervous system effects. It has no known drug-drug interactions, an advantage for patients taking many medications. Because these qualities may provide added benefit when treating patients with symptoms associated with overactive bladder (OAB) and urge incontinence, we studied the effectiveness of trospium in treating these conditions.

MATERIALS AND METHODS

Patients with OAB with urge incontinence were randomized 1:1 to 20 mg trospium twice daily or placebo in this 12-week, multicenter, parallel, double-blind, placebo controlled trial. Dual primary end points were change in average number of toilet voids and change in urge incontinent episodes per 24 hours. Secondary efficacy variables were change in average of volume per void, voiding urge severity, urinations during day and night, time to onset of action and change in Incontinence Impact Questionnaire.

RESULTS

A total of 523 patients were entered at 51 sites. Trospium significantly decreased average frequency of toilet voids and urge incontinent episodes compared to placebo. It significantly increased average volume per void, and decreased average urge severity and daytime frequency. All effects occurred by week 1 and all were sustained throughout the study. Nocturnal frequency decreased significantly by week 4 and Incontinence Impact Questionnaire scores improved at week 12. Trospium was well tolerated.

CONCLUSIONS

Trospium was found to have sustained effectiveness beginning at the end of week 1 in decreasing the number of voids, urge incontinent episodes, total daily micturitions and urge severity, and in increasing volume per void. It also improved symptoms of OAB and quality of life.