Persistence with antimuscarinic therapy in patients with overactive bladder

Risk of overactive bladder after hysterectomy for uterine fibroids

INTRODUCTION AND HYPOTHESIS

We evaluated the association between previous hysterectomy for uterine fibroids and the risk of developing overactive bladder (OAB).

METHODS

We used national health insurance data. The hysterectomy group (aged 40 to 59) comprised patients who underwent hysterectomy for uterine leiomyoma or adenomyosis between 1 January 2011 and 31 December 2014, and the control group (aged 40 to 59) comprised patients who visited a medical facility for a checkup during the same time period. Propensity score matching (PSM, 1:1) was performed to balance confounders. OAB events were defined by drug prescriptions (beta 3 agonist or anticholinergics) for more than 1 month based on previous studies.

RESULTS

After matching, 58,195 cases (hysterectomy group) and 58,195 controls (nonhysterectomy group) were enrolled. The mean follow-up period was 7.9 years in the nonhysterectomy group and 8.0 years in the hysterectomy group. There was no significant difference in the rate of OAB development between the groups (0.3% vs 0.3%; p=0.061). Additionally, compared with the nonhysterectomy group (hazard ratio: 1 (reference)), hysterectomy without adnexal surgery (hazard ratio: 1.169 [0.915-1.493]) and hysterectomy with adnexal surgery (hazard ratio: 1.342 [0.83-2.171]) did not significantly increase the risk of OAB after adjusting for confounders; this relationship remained nonsignificant after stratifying patients according to age group.

CONCLUSIONS

Previous hysterectomy with or without adnexal surgery for the treatment of uterine fibroids did not increase the risk of developing OAB, defined as drug therapy lasting more than 1 month.

Why Patients Fall Through the Cracks: Assessment of Patients' Overactive Bladder Treatment

Objective: Despite an established treatment algorithm for overactive bladder (OAB), it is unclear how many patients proceed through each step. Our objective was to evaluate the percentage of patients receiving each step of care and identify reasons why patients did not receive certain treatments. Methods: This was a retrospective cohort study with cross-sectional survey of new OAB patients. The medical record was queried for relevant patient characteristics and documentation of conservative, medical, and third-line therapies. In the survey, patients were asked about current bladder symptoms and reasons why they did not use certain treatments. Descriptive statistics were used for analysis. Results: One hundred eleven patients met the inclusion criteria; the most common diagnosis was mixed incontinence (40%, n = 45). The median number of visits for OAB was 2 (range 1-8). On retrospective analysis, 64% (71) of patients had documented attempts at conservative therapy. Seventy-six percent (84) of patients attempted medical therapy, and only 11% (12) progressed to any third-line therapy. Fifty-nine percent (64) of eligible patients responded to the survey. Fifty-three percent (34) of respondents reported persistent moderate to very severe bother due to bladder symptoms. Thirty percent to fifty percent of patients who did not attempt one or more of the three levels of OAB therapy reported that they were never offered that treatment option. Conclusions: Many patients do not progress to the next steps in OAB therapy despite failure of more conservative treatments. Barriers to care included limited follow-up and education about other therapy options. A formalized institutional care pathway may lead to improved OAB treatment.

Effect of oxybutynin patch versus mirabegron on nocturia-related quality of life in female overactive bladder patients: A multicenter randomized trial

OBJECTIVES

To investigate the effect of oxybutynin patch versus β3-adrenoceptor agonist mirabegron on nocturia-related quality of life in female overactive bladder patients.

METHODS

In the present study, female overactive bladder patients were enrolled. The patients were randomly allocated into two groups: the oxybutynin patch group and the mirabegron group. Each of the drugs was given for 8 weeks. The changes in the total Nocturia Quality of Life Questionnaire score were evaluated. Parameters on a frequency volume chart were also evaluated.

RESULTS

In total, 100 patients (51 oxybutynin patch, 49 mirabegron) were treated with oxybutynin patch or mirabegron. The changes in the Nocturia Quality of Life Questionnaire score 4 weeks after administration were 3.8 ± 18.6 and 8.7 ± 13.1 with the oxybutynin patch group and the mirabegron group, respectively, which were significantly higher than those at the baseline. Furthermore, the changes in the Nocturia Quality of Life Questionnaire score 8 weeks after administration were 4.3 ± 16.5 and 7.7 ± 12.3, respectively. A statistical difference was seen only in the mirabegron group. Regarding the Nocturia Quality of Life Questionnaire subscores, oxybutynin patch and mirabegron significantly improved the Nocturia Quality of Life Questionnaire bother/concern subscore 4 and 8 weeks after administration, whereas the Nocturia Quality of Life Questionnaire sleep/energy subscore was not significantly improved in each period. Eight weeks after administration, 24-h frequency, 24-h urinary urgency and mean voided urine volume were improved in both groups statistically.

CONCLUSIONS

The oxybutynin patch improves quality of life, focusing mainly on nocturia by improving the bother/concern subscores of the Nocturia Quality of Life Questionnaire in the short term.

A Retrospective Case Series of High-Frequency Spinal Cord Stimulation (HF10-SCS) in Neurogenic Bladder Incontinence

BACKGROUND

Current treatment options for bladder disorders of neurogenic etiology often leave unsatisfactory results. Therefore, new and effective treatments must be investigated. High-frequency spinal cord stimulation (HF-SCS) at 10 kHz has proven to be effective in the treatment of refractory chronic back and leg pain.

OBJECTIVE

To evaluate the efficacy of HF-SCS at 10 kHz in alleviating lower urinary tract dysfunction and bladder incontinence in 5 patients with underlying neurological disease or spinal cord injury, through retrospective study.

METHODS

Urodynamic parameters such as voiding frequency, residual volume, episodes of incontinence, and the patients' subjective impression impairment of life were assessed and compared pre- and postoperatively. Reduction in pain intensity was assessed as change on the Numeric Rating Scale (NRS).

RESULTS

All 5 patients had significantly positive outcomes. Episodes of leakage per day improved by 83% on average. Quality of life questionnaires and subjective bother scale revealed an improvement of 36% and 57%, respectively. Individual symptoms among the patient group such as residual volume also responded to the treatment as well. Mean pain NRS of 8.6 cm was reduced to 3.9 cm (55%) at 6 mo follow-up.

CONCLUSION

HF-SCS at 10 kHz significantly alleviated symptoms of neurogenic bladder incontinence in patients suffering from neurological disease or spinal cord injury. However, larger and prospective, randomized studies are necessary to make a clear statement regarding the efficacy of this therapy in lower urinary tract dysfunction and bladder incontinence.

Spinal cord stimulation for the restoration of bladder function after spinal cord injury

Spinal cord injury (SCI) results in the inability to empty the bladder voluntarily, and neurogenic detrusor overactivity (NDO) and detrusor sphincter dyssynergia (DSD) negatively impact both the health and quality of life of persons with SCI. Current approaches to treat bladder dysfunction in persons with SCI, including self-catheterisation and anticholinergic medications, are inadequate, and novel approaches are required to restore continence with increased bladder capacity, as well as to provide predictable and efficient on-demand voiding. Improvements in bladder function following SCI have been documented using a number of different modalities of spinal cord stimulation (SCS) in both persons with SCI and animal models, including SCS alone or SCS with concomitant activity-based training. Improvements include increased volitional voiding, voided volumes, bladder capacity, and quality of life, as well as decreases in NDO and DSD. Further, SCS is a well-developed therapy for chronic pain, and existing Food And Drug Administration (FDA)-approved devices provide a clear pathway to sustainable commercial availability and impact. However, the effective stimulation parameters and the appropriate timing and location of stimulation for SCS-mediated restoration of bladder function require further study, and studies are needed to determine underlying mechanisms of action.

Italian real-life clinical setting: the persistence and adherence with mirabegron in women with overactive bladder

INTRODUCTION AND HYPOTHESIS

The aims of this study were to evaluate the persistence, the adherence on treatment with mirabegron, the reasons for the interruption in patients with overactive bladder syndrome (OAB) and their satisfaction.

METHODS

This was an Italian multicentre prospective study. Four tertiary urological centers were involved. We included women with no neurogenic OAB symptoms already in therapy with once-daily mirabegron 50 mg for 1 month. They were followed up at 1, 3 and 6 months post-treatment with uroflowmetry with voiding diary for 3 days and post-void residual measurement. They completed self-administered Overactive Bladder questionnaire short form (OABq), Morisky Medication Adherence Scale-4 short form (MMAS), Patient Global Impression-Improvement questionnaire. Patients were divided in OAB wet and OAB dry groups, and in treatment-naive and treatment-experienced groups.

RESULTS

Between January 2018 and July 2018, 80 patients with OAB were included. Fifteen (18.7%) patients continued the treatment for 6 months; 17.5% interrupted the therapy before 1 month: 30% within the third month, while, 33.7% after 1 month. The median time to discontinuation with mirabegron was 62.5 days. The mean adherence was 0.42 ± 0.33, median MMAS was 2 (0-4). The adherence was significantly greater in treatment-naïve (22.4%) than treatment-experienced (6.5%) patients, without statistically significant differences in the different OAB form. The cost is the main cause of interruption of therapy (50% of cases).There was an improvement of OABqSF score and PGI-I score.

CONCLUSION

In Italy, the cost compromises adherence and persistence of therapy with mirabegron despite the good functional outcomes.

A Nordic registry-based study of drug treatment patterns in overactive bladder patients

Aim: To describe treatment patterns in Denmark, Norway and Sweden for patients receiving overactive bladder (OAB) pharmacotherapy.Methods: This was a prospective, multinational, registry-based study involving three nationwide prescribed drug registries (sample size 6000 patients per country), performed between 1 January and 30 June 2014. Patients were followed prospectively for 12 months after first pick-up of index medication. The primary objective was to evaluate the proportion of patients picking up first refill of index medication. Secondary objectives included evaluation of the average number of pick-ups collected during 1 year and time to discontinuation of index medication.Results: A high proportion of patients in the three Nordic countries picked up a first refill of OAB medication: 64-75% for mirabegron and 84-95% for individual antimuscarinics. Amongst treatment-naïve patients, the proportion picking up their first mirabegron refill was 60-64%; for individual antimuscarinics it was 30-63%. Mean number of pick-ups during 1 year ranged from 3.5-5.0 for mirabegron across the countries and for individual antimuscarinics from 3.8-12.3. Median time to discontinuation for mirabegron ranged from 140 (Denmark) to 207 days (Norway) and, for individual antimuscarinics (solifenacin), from 182 (Denmark) to 355 days (Sweden). At 12 months, the proportion of patients still on treatment with mirabegron and antimuscarinics was 21% and 38%, respectively.Conclusions: Treatment patterns in patients with OAB picking up a mirabegron or antimuscarinic prescription in Denmark, Norway and Sweden indicate that persistence remains a challenge.

Administration of leuprolide acetate, a GnRH agonist, improves urodynamic parameters in ovariectomized rats

AIM

To evaluate the effects of a treatment with leuprolide acetate (LA) on bladder overactivity as well as the expression of gonadotropin releasing hormone receptor (GnRH-R), and neurofilaments NF68 and NF200 in female rats with overactive bladder induced by castration.

METHODS

Changes in the urodynamic parameters were determined in SHAM, ovariectomized (OVX) and ovariectomized rats treated with LA (OVX-LA). A semi-quantitative analysis for the expression pattern of GnRH-R and neurofilaments NF68 and NF200 were determined.

RESULTS

Forty-three days after ovariectomy, rats from the OVX group have significant lower values for intercontractile interval (ICI) and compliance (C); as well as higher values for basal bladder pressure (BP) and frequency of non-voiding contractions (NVC). The systemic application of LA increased voiding volume (Vv) and pressure threshold (ThP) in the OVX-LA animals. The application of LA reduced the high frequency of NVC in the OVX rats. No significant differences were found for Vv and NVCs between the OVX-LA vs SHAM groups. At the mid part of the bladder, the presence of GnRH-R was evidenced in the urothelium of the SHAM group. The OVX animals showed different pattern of immunolabeling for GnRH-R as well as for neurofilaments NF200 and NF68, whereas in the OVX-LA group the immunofluorescence pattern was similar to the one seen in SHAM bladders (P < 0.05 for OVX vs OVX + LA).

CONCLUSIONS

the results suggest that systemic application of LA can improve bladder dysfunction in castrated rats, and perhaps considered as a treatment for overactive bladder conditions secondary to menopause.

An investigation of factors predicting the type of bladder antimuscarinics initiated in Medicare nursing homes residents

Background

To examine factors predicting type of bladder antimuscarinics (BAM) initiated in nursing home (NH) residents.

Methods

Incident BAM initiators following NH admission were identified by constructing a retrospective cohort from Medicare files and Minimum Data Set (MDS). Participants included all residents 65 years and older admitted in Medicare-certified NH between January 1, 2007 and December 31, 2008 who were prescribed BAM and had continuous Medicare (Part A, B, and D) enrollment. Patient characteristics, medications, and comorbidities were derived from Medicare enrollment and claims. NH characteristics and health status were derived from MDS assessments. The outcome was defined as type of BAM initiated after admission (selective, non-selective extended release, non-selective immediate release). Multinomial logistic regression using generalized estimating equation methodology determined which factors predicted the type of BAM initiated.

Results

Twelve thousand eight hundred ninety-nine NH residents initiating BAM therapy were identified; 13.38% of new users were prescribed selective BAM, 45.56% non-selective extended release, and 41.07% non-selective immediate release medications. In both sexes, significant predictors of BAM included region of nursing home, body mass index, cognitive performance score, frailty measures, activities of daily living, and measures of bladder continence. In women, history of fracture and fall-related injuries were significant predictors of type of BAM use, while race and indicators of balance were significant predictors of type of BAM use in men. Non-pharmacological continence management strategies were not predictive of type of BAM initiation.

Conclusions

Several factors are important in predicting type of BAM initiation in both women and men, but other factors are sex-specific. Some observed factors predicting the type of BAM initiated, such as other medications use, body mass index, or provider-related factors are potentially modifiable and could be used in targeted interventions to help optimize BAM use in this population.

Trial registration

Not applicable.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-017-0690-2) contains supplementary material, which is available to authorized users.

Frequent nocturia episodes, a suboptimal response to treatment, and small bladder capacity predict the need for persistent antimuscarinic therapy or re-treatment after discontinuation of antimuscarinics in female overactive bladder

OBJECTIVE

The aim of the study was to investigate predictive factors of the need for persistent antimuscarinic therapy or re-treatment (PR) after discontinuation of antimuscarinic therapy for women with overactive bladder syndrome (OAB).

METHODS

All consecutive OAB women were enrolled in a prospective cohort study, and treated with solifenacin for 12 weeks in a University Hospital. Factors affecting PR were analyzed by Cox regression analysis.

RESULTS

A total of 122 women were enrolled, and 107 women underwent 12-week solifenacin treatment. The dropout rate was 12.3%. The median follow-up period was 20.4 weeks (25-75 interquartile range: 16-102.3 wk). Twenty-seven (25%) women had PR. The median PR-free interval was 125.4 weeks (95% CI = 58.4 to - wk). Nocturia episodes (hazard ratio = 1.54), a suboptimal response (hazard ratio = 2.53), and the strong-desire volume (hazard ratio = 0.992) were independent predictors of PR by Cox backward stepwise regression analysis. The areas under the receiver-operating characteristic curves for nocturia episodes, a suboptimal response, and the strong-desire volume to predict PR were only 0.65, 0.63, and 0.59, respectively. In addition, normalized urinary nerve growth factor level was not significant (hazard ratio = 1.005, P = 0.68) for predicting PR. Furthermore, normalized urodynamic findings did not correlate with PR, a suboptimal response, or changes of Overactive Bladder Symptom Score and urinary nerve growth factor level.

CONCLUSIONS

Frequent nocturia episodes, a suboptimal response, and small bladder capacity may predict PR after solifenacin treatment. These findings may serve as an initial guide in consultation regarding the treatment of OAB.

Positive association of female overactive bladder symptoms and estrogen deprivation: A nationwide population-based cohort study in Taiwan

OBJECTIVE

Estrogen is considered to be a unique hormone in females that has an impact on voiding function. Animal models and clinical epidemiologic studies showed high correlation between estrogen deficiency and female overactive bladder (OAB) symptoms. We designed a population-based cohort study from a national health database to assess the association of estrogen deprivation therapy and female OAB.

MATERIALS AND METHODS

This study examined the records of 16,128 patients ranging in age from 18 to 40 that were included in the Taiwan National Health Insurance Research Database (NHIRD) in the years between 2001 and 2010. Of these, 1008 had breast cancer with hormone therapy only and the other 15,120 controls did not have breast cancer or hormone therapy. All patients with neurologic diseases and those with pre-existing OAB identified by information in the NHIRD database were excluded. OAB was defined by medications prescribed for at least 1 month. Risk of new onset OAB in the breast cancer and nonbreast cancer groups was estimated. Fourteen patients (1.4%) experienced OAB in the breast cancer group. Overall, breast cancer with estrogen deprivation therapy increased the risk of OAB by 14.37-fold (adjusted hazard ratio, 95% confidence interval 7.06-29.27). Subgroup analysis showed that in the older age breast cancer group (36-40), a lower Charlson comorbidity index (CCI) score and antidepressant medication use for at least 30 days had an impact on the increase of OAB risk. After adjustment of variables, the higher CCI and the use of antipsychotic drugs increased risk of OAB 3.45-fold and 7.45-fold, respectively. The Kaplan-Meier analysis of OAB-free survival in the breast cancer group showed a significant time-dependent increase in incidence of OAB.

CONCLUSION

Estrogen deprivation in young patients with breast cancer increased the risk of OAB. The OAB development rate was steady and fast in the beginning 3 years after estrogen deprivation. This result indicates a role of estrogen in the modulation of female voiding function.

Safety and efficacy of mirabegron in daily clinical practice: a prospective observational study

OBJECTIVE

To determine risks associated with prescribing mirabegron, the first-in-class β3-adrenoreceptor agonist, to non-selected female patients with overactive bladder.

STUDY DESIGN

Routine female patients seeking treatment for overactive bladder (n=221) in a urology/gynecology outpatient clinic. Data on adverse events, cardiovascular outcomes, condition specific symptoms and drug discontinuation was collected at two months follow-up (FU). Non-parametric statistics was used as appropriate. Odds ratios (ORs) with 95% confidence intervals (CIs) for outcome association analyses using logistic regression.

RESULTS

16 patients (7.2%) discontinued treatment because of side effects. There were no significant associations between cardiovascular adverse events and pre-existing cardiovascular disease (OR 0.3, 95% CI 0.3-2.6), or pre-existing ECG abnormalities (OR 2.3, 95% CI 0.3-16.3). At FU ECGs there were no de novo cases of tachyarrhythmias and no significant difference in mean QTc between baseline (403ms, SD 21.7) and the 2 months follow-up ECG (403ms, SD 20.3) (p=0.75). There was a significant decrease in the mean systolic blood pressure (p=0.03) but no significant change in mean diastolic pressure (p=0.8) or heart rates (p=0.2) from baseline to FU. Overactive bladder specific symptoms and quality of life improved significantly (p<0.001 respectively).

CONCLUSIONS

Mirabegron treatment is associated with a satisfactory cardiovascular safety profile, as well as, significant symptomatic improvement also in a heterogeneous population of non-selected women with overactive bladder presenting in everyday clinical practice.

Cost-effectiveness analysis of onabotulinumtoxinA (BOTOX(®)) for the management of urinary incontinence in adults with neurogenic detrusor overactivity: a UK perspective

OBJECTIVES

To evaluate the cost effectiveness of onabotulinumtoxinA (BOTOX(®), 200 units [200 U]) for the management of urinary incontinence (UI) in adults with neurogenic detrusor overactivity (NDO) due to subcervical spinal cord injury or multiple sclerosis that is not adequately managed with anticholinergic drugs (ACHDs).

PERSPECTIVE

UK National Health Service (NHS) perspective.

METHODS

A Markov state-transition model was developed, which compared onabotulinumtoxinA + best supportive care (BSC) with BSC alone (comprising behavioural therapy and pads, alone or in combination with clean intermittent catheterization and possibly with ACHDs). Non-responders were eligible for invasive procedures. Health states were defined according to the reduction in UI episodes. Efficacy data and estimates of resource utilization were pooled from 468 patients on onabotulinumtoxinA in two phase III clinical trials. Drug costs (2013) and administration costs (NHS Reference Costs 2011-2012) were obtained from published sources. The time horizon of the model was 5 years, and costs and benefits were discounted at 3.5%. Scenario, one-way and probabilistic sensitivity analyses (PSAs) were conducted to explore uncertainties around the assumptions.

RESULTS

In the base case, treatment with onabotulinumtoxinA + BSC over 5 years was associated with an increase in costs of £1,689 and an increase in quality-adjusted life-years (QALYs) of 0.4, compared with BSC alone, resulting in an incremental cost-effectiveness ratio of £3,850 per QALY gained. Sensitivity analyses showed that utility values had the greatest influence on model results. PSA suggests that onabotulinumtoxinA + BSC had a 100 % probability of being cost effective at a willingness to pay of <£20,000.

CONCLUSION

For adult patients with NDO who are not adequately managed with ACHDs, onabotulinumtoxinA + BSC appears to be a cost-effective use of resources in the UK NHS.

Medication adherence in the management of nocturia: challenges and solutions

OBJECTIVE

Nocturia affects millions of men and women. No prior reviews or meta-analyses have explored the issue of adherence in nocturia patients. The objective of our study was to examine the attributes and their interaction that might impact pharmacological adherence in nocturia care using a conceptual model of adherence.

MATERIALS AND METHODS

A literature search of the Medline, PubMed, Embase, PsycInfo, and CINAHL databases for studies published between January 1990 and June 2014 was conducted. We developed a conceptual model in order to facilitate our review.

RESULTS

Currently, multiple treatment options for nocturia exist, depending on the underlying cause. Adherence to nocturia treatment and outcomes are complex and intertwined, and nonadherence to nocturia treatment is common. In 15 studies meeting eligibility criteria, behavioral and pharmacologic interventions for nocturia were associated with reduced nocturia symptoms. Urinary symptoms that are associated with nocturia need individualized management depending on renal and hepatic function, medical comorbidities, and ongoing medication use in a patient. Another important factor related to adherence is the bother. Although nocturia is defined as nighttime-voiding frequency of one or more, not all persons may find this bothersome. The degree of bother is subjective, and may change from person to person. However, there is no information related to the association between bother and adherence to medication or behavioral treatments for nocturia. Medication dosing convenience, preference, and cost play important roles in adherence. We present a patient-centered conceptual model that brings together the various dimensions of medication adherence for nocturia.

CONCLUSION

Few studies have explored adherence to medication and related factors in the care of nocturia. Our conceptual model can aid development of interventions to improve adherence to nocturia medications.

Persistence with solifenacin add-on therapy in men with benign prostate obstruction and residual symptoms of overactive bladder after tamsulosin monotherapy

AIMS

In spite of the reported efficacy and safety of antimuscarinics in men with OAB (overactive bladder) and BPO (benign prostatic obstruction), many patients do not persist with the treatment. We aimed to evaluate persistence and the reasons for the discontinuation of solifenacin add-on therapy in men with residual symptoms of OAB after tamsulosin monotherapy for BPO in a real clinical environment.

METHODS

Men aged ≥ 45 years with IPSS ≥ 12 and symptoms of OAB (OAB-V8 ≥ 8, micturition ≥ 8/24 h, urgency ≥ 2/24 h) were prescribed tamsulosin 0.2 mg. After 4 weeks, men who had residual symptoms of OAB (OAB-V8 ≥ 8, micturition ≥ 8/24 h, urgency ≥ 1/24 h) and reported that they were 'dissatisfied' or 'a little satisfied' with the therapy were enrolled and prescribed solifenacin 5 mg in combination with tamsulosin. After 52 weeks, persistence and the reasons for the discontinuation of solifenacin were evaluated. Factors related to persistence were analysed.

RESULTS

Of the 305 men who had been treated with tamsulosin, 176 were prescribed solifenacin. After 52 weeks, 44 (25%) remained on solifenacin therapy. Of the 132 who discontinued solifenacin, 85 were evaluated on the reason for discontinuation. The three most common reasons for discontinuation were adverse events (AEs) (35%), lack of efficacy (33%), and improvement in symptoms (16%). The aggravation of voiding symptoms was the most common AE leading to discontinuation. Retention was observed in 11 men. None of the demographical or clinical characteristics were significantly related to persistence.

CONCLUSIONS

Only 25% men with OAB and BPO remained on antimuscarinic add-on therapy after 1 year, mostly because of AEs and lack of efficacy. Realistic data should be added to what is already known about antimuscarinic treatment in men by including patients who were excluded or who dropped out of well-designed clinical trials.

Tolterodine extended release in the treatment of male OAB/storage LUTS: a systematic review

Background

Overactive bladder (OAB)/ storage lower urinary tract symptoms (LUTS) have a high prevalence affecting up to 90% of men over 80 years. The role of sufficient therapies appears crucial. In the present review, we analyzed the mechanism of action of tolterodine extended-release (ER) with the aim to clarify its efficacy and safety profile, as compared to other active treatments of OAB/storage LUTS.

Methods

A wide Medline search was performed including the combination of following words: “LUTS”, “BPH”, “OAB”, “antimuscarinic”, “tolterodine”, “tolterodine ER”. IPSS, IPSS storage sub-score and IPSS QoL (International Prostate Symptom Score) were the validated efficacy outcomes. In addition, the numbers of urgency episodes/24 h, urgency incontinence episodes/24 h, incontinence episodes/24 h and pad use were considered. We also evaluated the most common adverse events (AEs) reported for tolterodine ER.

Results

Of 128 retrieved articles, 109 were excluded. The efficacy and tolerability of tolterodine ER Vs. tolterodine IR have been evaluated in a multicenter, double-blind, randomized placebo controlled study in 1529 patients with OAB. A 71% mean reduction in urgency incontinence episodes was found in the tolterodine ER group compared to a 60% reduction in the tolterodine IR (p < 0.05). Few studies evaluated the clinical efficacy of α-blocker/tolterodine combination therapy. In patients with large prostates (prostate volume >29 cc) only the combination therapy significantly reduced 24-h voiding frequency (2.8 vs. 1.7 with tamsulosin, 1.4 with tolterodine, or 1.6 with placebo). A recent meta-analysis evaluating tolterodine in comparison with other antimuscarinic drugs demonstrated that tolterodine ER was significantly more effective than placebo in reducing micturition/24 h, urinary leakage episodes/24 h, urgency episodes/24 h, and urgency incontinence episodes/24 h. With regard to adverse events, tolterodine ER was associated with a good adverse event profile resulting in the third most favorable antimuscarinic. Antimuscarinic drugs are the mainstay of pharmacological therapy for OAB / storage LUTS; several studies have demonstrated that tolterodine ER is an effective and well tolerated formulation of this class of treatment.

Conclusion

Tolterodine ER resulted effective in reducing frequency urgency and nocturia and urinary leakage in male patients with OAB/storage LUTS. Dry mouth and constipation are the most frequently reported adverse events.

Antimuscarinic persistence patterns in newly treated patients with overactive bladder: a retrospective comparative analysis

INTRODUCTION AND HYPOTHESIS

Treatment persistence is low in patients with overactive bladder (OAB), but persistence may vary among antimuscarinic agents. This study compared treatment persistence in patients with OAB receiving fesoterodine, solifenacin, or tolterodine as their initial OAB prescription in a routine clinical practice setting.

METHODS

This retrospective study used medical records from primary healthcare centers in three locations in Spain; records from patients aged ≥18 years with a diagnosis of OAB who initiated antimuscarinic treatment for OAB (fesoterodine, tolterodine, or solifenacin) were included. The first prescription of one of the OAB study medications was considered the index date; patients were followed for ≥52 weeks. Persistence was estimated using Kaplan-Meier curves and Cox proportional hazard regression models, adjusting for covariates.

RESULTS

A total of 1,971 records of patients (58.3 % women; mean age 70.1 years) initiating treatment with fesoterodine (n = 302), solifenacin (n = 952), or tolterodine (n = 717) were included. Unadjusted mean (±SD) treatment duration was 31.5 ± 17.6 weeks for fesoterodine, 29.9 ± 21.4 for solifenacin and 29.0 ± 21.6 for tolterodine (p = 0.217). At week 52, 35.8 % of fesoterodine-treated patients remained on their initial therapy, versus 31.9 % of solifenacin-treated (hazard ratio [HR], 1.24; 95 % CI, 1.05-1.47; p = 0.011) and 30.9 % of tolterodine-treated (HR = 1.28; 95 % CI, 1.07-1.52; p = 0.006) patients. Findings were consistent when the definition for discontinuation was varied.

CONCLUSIONS

Overall persistence at week 52 was low, but the cumulative probability of persisting with initial therapy was significantly higher for fesoterodine than for solifenacin or tolterodine in clinical practice in Spain.

The satisfaction of patients with refractory idiopathic overactive bladder with onabotulinumtoxinA and augmentation cystoplasty

Objective

To assess the satisfaction of patients with refractory idiopathic overactive bladder (OAB) with two treatment methods, onabotulinumtoxinA (oBTX) and augmentation ileocystoplasty (AC).

Patients and methods

This prospective study included patients with refractory idiopathic OAB for >6 months and a urodynamic diagnosis of OAB. Oral pharmacotherapy had failed in all patients. Patients with any suspected neurological disorder were excluded. Before the procedure, patients completed the Urogenital Distress Inventory (UDI-6) and modified Incontinence Impact Questionnaire (IIQ-7), a neurological evaluation, a urodynamic study and their postvoid residual urine volume was measured. Patients were assigned to receive oBTX or AC, depending on patient’s preference. Follow-up visits were at 6 weeks and 3 and 6 months after the procedure. The OAB Satisfaction questionnaire (OAB-SAT-q) was used to assess satisfaction after the procedure.

Results

In all, 31 patients with refractory OAB were included, 16 in the oBTX group and 15 in the AC group. There was no significant difference between the groups in mean age, baseline OAB symptoms and urodynamic values. There were significant improvements in urinary symptoms (UDI-6) and quality of life (IIQ-7) after both procedures (except in the domain enquiring about difficulty, which significantly worsened after AC). Of the 16 patients, 15/16 and seven of 15 were completely dry after AC and oBTX, respectively. The overall and individual scores of the OAB-SAT-q were significantly higher among patients treated with AC than with oBTX. The incidence of the de novo need to use clean intermittent catheterisation after oBTX and AC was two of 16 and four of 15, respectively.

Conclusions

Both procedures are effective in improving the symptoms of OAB and of quality of life, but patients were more satisfied with AC than oBTX therapy.

Efficacy and safety of repeated dosing of netupitant, a neurokinin-1 receptor antagonist, in treating overactive bladder

AIM

NK-1 receptors in sensory nerves, the spinal cord and bladder smooth muscle participate in complex sensory mechanisms that regulate bladder activity. This study was designed to assess the efficacy and safety of a new NK-1 receptor antagonist, netupitant, in patients with OAB.

METHODS

This was a phase II, multicenter, double-blind study in which adults with OAB symptoms >6 months were randomized to receive 1 of 3 doses of netupitant (50, 100, 200 mg) or placebo once daily for 8 weeks. The primary efficacy endpoint was percentage change from baseline in average number of daily micturitions at week 8. Urinary incontinence, urge urinary incontinence (UUI), and urgency episodes were also assessed.

RESULTS

The primary efficacy endpoint was similar in the treatment groups (-13.85 for placebo to -16.17 in the netupitant 200 mg group) with no statistically significant differences between netupitant and placebo. The same was true for most secondary endpoints although a significant difference for improvement in UUI episodes and a trend for the greatest decrease in urgency episodes were seen in the netupitant 100 mg group. Netupitant was well tolerated with most treatment emergent adverse events (AEs) being mild. While the overall incidence of AEs increased with netupitant dose, there was no evidence for this dose dependency based on relationship to treatment, intensity, or time to onset.

CONCLUSIONS

The study failed to demonstrate superiority of netupitant versus placebo in decreasing OAB symptoms, despite a trend favoring netupitant 100 mg. There were no safety concerns with daily administration of netupitant over 8 weeks.

[New perspectives of treatment with fesoterodine fumarate in patients with overactive bladder]

OBJECTIVE

Evaluate the effect of the treatment with fesoterodine fumarate in patients with overactive bladder, as an alternative in case of failure of the usual anticholinergic treatment, due to either lack of therapeutic efficacy or due to intolerance to side effects.

MATERIAL AND METHOD

A retrospective review of 158 patients with overactive bladder was carried out. The patients were divided into two groups; the first group; 56 patients where the anticholinergic treatment showed to be ineffective, and the second group; 102 patients who presented intolerance to anticholinergic side effects.

RESULTS

For the first group where fesoterodine fumarate was used to improve effectiveness of the anticholinergics, improvement in the components of urinary urgency (p=0.001), insufficient emptying (p=0.001), incontinence (p=0.009), and in the number of pads/day (p<0.001) was detected. As to the second group where fesoterodine fumarate was used as an alternative to anticholinergics to avoid side effects, a high reduction in the incidence of dry mouth (p<0.001) and constipation (p=0.015) was seen, as well as a significant clinical improvement.

CONCLUSION

Fesoterodine fumarate is an optimal treatment option when the clinical response to anticholinergics has not been satisfactory, either by the lack of therapeutic action or by intolerance to side effects, and especially when the treatment is expected to be long.

Success rates, quality of life, and feasibility of sacral nerve stimulation in elderly patients: 1-year follow-up

INTRODUCTION AND HYPOTHESIS

Urgency urinary incontinence (UUI) frequently occurs in elderly. International guidelines recommend pharmacological therapy as first-line treatment, but elderly do not respond in many cases. The purpose of this study was to report cure rates, quality of life, and feasibility of sacral neurostimulation (SNS) as an alternative option in the elderly.

MATERIALS AND METHODS

From October 2008 to April 2010, women >65 years with UUI who were refractory to pharmacological treatments were enrolled in this study and underwent SNS. At 12 months after surgery, patients were asked to compile a 3-day voiding diary and a urogynecologic standardized questionnaire: the Overactive Bladder Questionnaire (OAB-q).

RESULTS

Eighteen patients met our inclusion criteria. Fifteen (83.3 %) underwent implantation of the neuromodulator. Twelve months after surgery, an overall success rate of 83.3 % was registered. A statistically significant difference (P<0.0001) between baseline and postsurgery OAB-q scores was recorded.

CONCLUSIONS

SNS can be considered an alternative treatment for UUI in older women.

Persistence with prescribed antimuscarinic therapy for overactive bladder: a UK experience

Study Type--Therapy (prevalence) Level of Evidence 2b. What's known on the subject? and What does the study add? Persistence with long-term medication in chronic diseases is typically low and that for overactive bladder medication is lower than average. Sub-optimal persistence is a major challenge for the successful management of overactive bladder. Using UK prescription data, persistence was generally low across the range of antimuscarinics. Patients aged 60 years and above were more likely to persist with prescribed oral antimuscarinic drugs than younger patients (40-59 years). Solifenacin was consistently associated with the highest rate of persistence compared with the other antimuscarinics included in the study

OBJECTIVES

• To describe the level of persistence for patients receiving antimuscarinics for overactive bladder (OAB) over a 12-month period based on real prescription data from the UK. • To investigate patterns of persistence with oral antimuscarinic drugs prescribed for OAB, across different age groups.

PATIENTS AND METHODS

• UK prescription data from a longitudinal patient database were analysed retrospectively to assess persistence with darifenacin, flavoxate, oxybutynin (extended release [ER] and immediate release [IR]), propiverine, solifenacin, tolterodine (ER/IR) and trospium. • Data were extracted from the medical records of >1,200,000 registered patients via general practice software, and anonymized prescription data were collated for all eligible patients with documented OAB (n = 4833). • Data were collected on patients who started treatment between January 2007 and December 2007 and were collected up to December 2008, to allow each patient a full 12-month potential treatment period. Failure of persistence was declared after a gap of at least 1.5 times the length of the period of the most recent prescription. • The analysis included only patients who were new to a course of treatment (i.e. who had not been prescribed that particular treatment or dosage for at least 6 months before the study period).

RESULTS

• The number of patients prescribed each antimuscarinic drug varied from 23 for darifenacin to 1758 for tolterodine ER. • The longest mean persistence was reported for solifenacin (187 days versus 77-157 days for the other treatments). • At 3 months, the proportions of patients still on their original treatment were: solifenacin 58%, darifenacin 52%, tolterodine ER 47%, propiverine 47%, tolterodine IR 46%, oxybutynin ER 44%, trospium 42%, oxybutynin IR 40%, flavoxate 28%. • At 12 months, the proportions of patients still on their original treatment were: solifenacin 35%, tolterodine ER 28%, propiverine 27%, oxybutynin ER 26%, trospium 26%, tolterodine IR 24%, oxybutynin IR 22%, darifenacin 17%, flavoxate 14%. • In a sub-analysis stratified by age, patients aged ≥ 60 years were more likely to persist with prescribed therapy over the 12-month period than those aged <60 years.

CONCLUSIONS

• Twelve months after the initial prescription, persistence rates with pharmacotherapy in the context of OAB are generally low. • Solifenacin was associated with higher levels of persistence compared with other prescribed antimuscarinic agents. • Older people are more likely than younger patients to persist with prescribed therapy. Further studies are required to understand this finding and why patients are more likely to persist with one drug rather than another.

An overview of the clinical use of antimuscarinics in the treatment of overactive bladder

Overactive bladder is a common and bothersome condition. Antimuscarinic agents, as a class, are the cornerstone of medical treatment of overactive bladder. They offer significant improvements in symptoms and patients' quality of life. Antimuscarinics are generally well tolerated with mild and predictable side effects. Available antimuscarinics have small, yet statistically significant, differences in their efficacy and tolerability profiles. In clinical practice, finding the agent that offers the optimum balance of efficacy and side effects for an individual patient remains the major challenge.

Cost-effectiveness analysis of antimuscarinics in the treatment of patients with overactive bladder in Spain: a decision-tree model

Background

Fesoterodine, a new once daily antimuscarinic, has proven to be an effective, safe, and well-tolerated treatment in patients with overactive bladder (OAB). To date, no analysis has evaluated the economic costs and benefits associated with fesoterodine, compared to antimuscarinics in Spain. The purpose of this analysis was to assess the economic value of OAB treatment with fesoterodine relative to extended release tolterodine and solifenacin, from the societal perspective.

Methods

The economic model was based on data from two 12-week, randomized, double-blind, and multicenter trials comparing fesoterodine and tolterodine extended released (ER). Treatment response rates for solifenacin were extracted from the published literature. Discontinuation and efficacy were based on the results of a 12-week multinational randomized clinical trial extrapolated to 52 weeks. Changes in health related quality of life were assessed with the King's Health Questionnaire, which was transformed into preference-based utility values. Medical costs included (expressed in € 2010) were antimuscarinics, physician visits, laboratory tests, incontinence pads and the costs of OAB-related comorbidities, fractures, skin infections, urinary tract infections, depression, and nursing home admissions associated with incontinence. Time lost from work was also considered. Univariate sensitivity analyses were also performed.

Results

At week 12, continents accounted for 50.6%, 40.6% and 47.2% of patients in the fesoterodine, tolterodine, and solifenacin groups, respectively. By week 52, the projected proportions of patients remaining on therapy were 33.1%, 26.5% and 30.8%, respectively. The projected quality- adjusted life years (QALY) gain (compared to baseline) over the 52-week simulation period were 0.01014, 0.00846 and 0.00957, respectively. The overall treatment cost was estimated at €1,937, €2,089 and €1,960 for fesoterodine, tolterodine and solifenacin, respectively. Therefore, treatment with fesoterodine resulted in similar overall costs and greater QALY gain than treatment with either tolterodine or solifenacin. Sensitivity analysis showed that these results were robust to all changes performed.

Conclusions

The results of this economic analysis suggest that fesoterodine is a cost-effective alternative to tolterodine and solifenacin for the treatment of patients with OAB in Spain. Fesoterodine provides additional health benefits while maintain a similar level of costs being a cost-effective treatment strategy from a societal perspective.

Falls risk reduction and treatment of overactive bladder symptoms with antimuscarinic agents: a scoping review

AIMS

Overactive bladder (OAB) symptoms are associated with falls and fractures in older adults and treatment with antimuscarinic agents may decrease this falls risk. Bladder-specific antimuscarinic agents may also adversely affect falls risk because of drug-related cognitive impairment. Thus, a tension between effective treatment, falls risk reduction, and increased falls risk is created. We conducted a scoping review to determine whether sufficient studies exist to warrant a full systematic review of falls risk reduction through treatment of OAB and to identify gaps in current research.

METHODS

Using an iterative scoping approach, a search of electronic databases was undertaken using key terms. Studies in any setting of older adults who had fallen or were at risk for falls and were provided pharmacological treatment of OAB to reduce of falls or falls risk were sought. Relevant articles were identified, reviewed, and used to map research activity regarding the pharmacological treatment of OAB in older adults and its relationship to falls and falls risk reduction.

RESULTS

Only one study met our initial inclusion criteria. Six additional studies were useful in identification research gaps, particularly in terms of outcome measures.

CONCLUSIONS

Insufficient evidence exists to recommend antimuscarinic treatment as a strategy for falls reduction, and the contribution of such agents to increased falls risk is unclear. Future studies of antimuscarinic agents for OAB must include measures of falls and falls risk and cognitive effects.

The market lifecycle of duloxetine for urinary incontinence in Norway

OBJECTIVE

To investigate the epidemiology of prescriptions for duloxetine for the treatment of stress urinary incontinence during its entire lifecycle in Norway (October 2004-May 2007), including the persistence of use of the drug and the prescribers.

DESIGN AND SETTING

Observational study in Norway.

SAMPLE

All prescriptions on duloxetine filled in Norwegian pharmacies.

METHODS

Data from the Norwegian Prescription Database.

MAIN OUTCOME MEASURE

Patient's age, unique identification, date of dispensing, data on specialty of the prescribing doctor, and number of packages purchased. Persistence of use of duloxetine was analyzed by grouping the months of first prescription filled into quarters of a year, from the fourth quarter of 2004 to the third quarter of 2007.

RESULTS

A total of 3,024 filled prescriptions were recorded of which 2,903 (96%) could be further analyzed, corresponding to 37 users per 100,000 women in the population. Each patient filled a mean of 3.4 prescriptions. The persistence of use was very low from the second quarter itself, and after 1 year only 12.5% of the patients still purchased the drug. Most prescriptions were written by GPs and gynecologists. A prescription database like ours consists of dispensed prescriptions and not drugs taken. We believe that these biases are of little importance for the main results.

CONCLUSIONS

Analyses from the national prescription database show that duloxetine had a low uptake on the market and a low persistence rate among the patients during its full lifecycle on the Norwegian market.

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.

A review of adherence to drug therapy in patients with overactive bladder

Drug therapy for overactive bladder (OAB) is associated with improvements in symptoms and quality of life, but the short- and long-term adherence and persistence is suboptimal. In this review we outline methods of measuring, and factors affecting, adherence to pharmacotherapy in patients with OAB. Clinical practice suggests that adherence rates reported in clinical trials are much greater than in real practice. Factors affecting adherence include psychological and social variables that might alter patients' perception of the benefits of taking medication, and the effect of comorbidity and polypharmacy. Whilst there is some evidence that lack of efficacy and side-effects are contributory, these additional factors are also important.

A randomized double-blind placebo-controlled multicentre study to explore the efficacy and safety of tamsulosin and tolterodine in women with overactive bladder syndrome

OBJECTIVES

To evaluate the efficacy of tamsulosin oral-controlled absorption system (OCAS) vs placebo in overactive bladder (OAB), to evaluate the safety and tolerability of once-daily dosing with tamsulosin OCAS, and to compare the efficacy and safety with tolterodine extended-release (ER).

PATIENTS AND METHODS

A parallel-group, multicentre, multinational study was conducted with a single-blind placebo run-in period of 2 weeks, followed by a randomized, double-blind, double-dummy active and placebo-controlled treatment period of 6 weeks; women (aged 18-70 years) with symptoms of OAB for >/= 3 months were recruited. Women were randomized to receive one of four doses of tamsulosin OCAS (0.25, 0.5, 1.0 or 1.5 mg), 4 mg of tolterodine ER, or placebo once daily for 6 weeks. The primary efficacy variable was the change in the mean number of voids/24 h. Secondary efficacy variables included change from baseline in; mean volume voided per void, mean number of incontinence episodes/24 h, mean number of urgency episodes/24 h and in quality of life (QoL), as assessed using the Kings Health Questionnaire (KHQ).

RESULTS

Overall, 364 women were randomized; the primary efficacy analysis showed that the difference from placebo in the mean number of voids/24 h was not statistically significant for tamsulosin OCAS 1.5 mg (P = 0.189). There was no statistically significant difference for tolterodine ER 4 mg vs placebo in the mean number of voids/24 h (P = 0.353). Similarly, for the secondary outcome variables there was no statistically significant difference between tamsulosin and placebo. Although women taking tolterodine ER 4 mg had a consistently greater increase in mean voided volume/void and consistent decreases in incontinence episodes/24 h, urgency episodes/24 h and episodes of nocturia/24 h, this was not statistically significant. There was no significant improvement in QoL scores across the treatment groups. Tamsulosin OCAS was well tolerated and the proportion of women discontinuing because of adverse events was low (4.7%).

CONCLUSION

Tamsulosin is not effective for treating OAB in women and the evidence from this study does not support its use on an empirical basis.

Purinoceptors as therapeutic targets for lower urinary tract dysfunction

Lower urinary tract symptoms (LUTS) are present in many common urological syndromes. However, their current suboptimal management by muscarinic and alpha(1)-adrenoceptor antagonists leaves a significant opportunity for the discovery and development of superior medicines. As potential targets for such therapeutics, purinoceptors have emerged over the last two decades from investigations that have established a prominent role for ATP in the regulation of urinary bladder function under normal and pathophysiological conditions. In particular, evidence suggests that ATP signaling via P2X(1) receptors participates in the efferent control of detrusor smooth muscle excitability, and that this function may be heightened in disease and aging. ATP also appears to be involved in bladder sensation, via activation of P2X(3) and P2X(2/3) receptors on sensory afferent neurons, both within the bladder itself and possibly at central synapses. Such findings are based on results from classical pharmacological and localization studies in non-human and human tissues, knockout mice, and studies using recently identified pharmacological antagonists--some of which possess attributes that offer the potential for optimization into candidate drug molecules. Based on recent advances in this field, it is clearly possible that the development of selective antagonists for these receptors will occur that could lead to therapies offering better relief of sensory and motor symptoms for patients, while minimizing the systemic side effects that limit current medicines.

Muscarinic receptors in the bladder: from basic research to therapeutics

Muscarinic receptor antagonists (antimuscarinics) serve as the cornerstone in the pharmacological management of overactive bladder (OAB) by relieving the symptoms of urgency, frequency and incontinence. These drugs operate primarily by antagonizing post-junctional excitatory muscarinic receptors (M(2)/M(3)) in the detrusor. The combination of pharmacological and gene knockout studies has greatly advanced our understanding of the functional role of muscarinic receptors in the bladder. M(3) receptors produce direct smooth muscle contraction by a mechanism that relies on entry of extracellular calcium through L-type channels and activation of a rho kinase. M(2) receptors, which predominate in number, appear to facilitate M(3)-mediated contractions. M(2) receptors can also produce bladder contractions indirectly by reversing cAMP-dependent beta-adrenoceptor-mediated relaxation, although the physiological role of beta-adrenoceptors in detrusor relaxation is controversial. Emerging evidence suggests that muscarinic receptors in the urothelium/suburothelium can modulate the release of certain factors, which in turn may affect bladder function at the efferent or afferent axis. Currently, oxybutynin, tolterodine, darifenacin, solifenacin and trospium are the five major antimuscarinics approved for the treatment of OAB. Comparative clinical studies have shown that oxybutynin and solifenacin may be marginally more effective than tolterodine, although the latter seems to be better tolerated. Pharmacokinetic-pharmacodynamic analyses using plasma concentrations of 'total drug' indicate that, at therapeutic doses, the clinical efficacy of darifenacin and solifenacin may be driven primarily by selective M(3) receptor occupation, whereas the pharmacodynamic effects of pan-selective molecules (such as tolterodine, trospium) may potentially involve multiple receptors, including M(2) and M(3). Furthermore, high M(3) receptor occupation is the likely explanation for the greater propensity of darifenacin and oxybutynin to cause dry mouth and/or constipation. Although the recently introduced drugs represent a significant improvement over older drugs, especially with respect to the convenience of dosing schedule, their overall efficacy and tolerability profile is still less than optimal and patient persistence with therapy is low. Recent advances in basic research have not yet offered a clear discovery path for improving the therapeutic index of antimuscarinic molecules. There is still an unmet need for an antimuscarinic medicine with superior clinical effectiveness that can translate into better persistence on therapy.