Does the Number of Previous Vaginal Deliveries Affect Overactive Bladder Symptoms and their Response to Treatment?

Sex and Gender Differences in the Pharmacology of the Overactive Urinary Bladder

Dysfunction of the lower urinary tract in general and the overactive bladder syndrome (OAB) in particular are prevalent and have major impact on the quality of life of the afflicted patients and their partners. We concisely review sex and gender differences in patients and animal models in physiological bladder function, its alterations in disease (mostly OAB), and its responses to treatment. Women appear to have a smaller functional bladder capacity and, therefore, must void more often than men. On the other hand, men have a greater bladder outlet resistance, which is partly attributed to a longer urethra and partly to the presence of the prostate. Sex and gender differences in bladder contractility appear small and were not found consistently. The ability of bladder smooth muscle to relax may be somewhat smaller in females. However, females are heavily underrepresented in experimental studies on bladder function. Stress urinary incontinence is found predominantly in women (particularly those after childbirth). OAB is similarly prevalent in men and women. Females seek treatment much more often and are overrepresented in clinical trials. Treatment responses in OAB patients are similar in both genders for oral medications, but improvements upon injections of onabotulinum toxin type A appear smaller in men. We conclude that there is no evidence for major sex and gender differences in bladder dysfunction as related to OAB and its treatment responses, but female animals are heavily underrepresented in experimental studies.

Weak association between arterial hypertension and overactive bladder baseline symptoms and treatment responses

While animal studies have suggested an association between the presence of hypertension and the presence and/or severity of overactive bladder syndrome (OAB) symptoms, little clinical data is available. We have conducted a pre-specified secondary analysis of a non-interventional study involving 4450 OAB patients being treated with solifenacin to explore the existence of an association between OAB and hypertension using three parallel and overlapping definitions of hypertension to enhance robustness of analysis. Regardless of definition, patients with hypertension were older and had greater OAB symptom severity in univariate analyses. In multiple regression models including age as explanatory covariate, most relationships held up but effect sizes of concomitant hypertension on OAB severity were small (odds ratios <1.35 in all cases) and were deemed to be unlikely of clinical relevance. % Changes in symptom severity were somewhat smaller in univariate analysis, but effect sizes were small. We conclude that OAB and arterial hypertension are associated but effect sizes are too small to justify adaptation of clinical practice for OAB patients with concomitant hypertension.

What Are Realistic Expectations to Become Free of Overactive Bladder Symptoms? Experience from Non-interventional Studies with Propiverine

INTRODUCTION

Unmet expectations are a major cause of perceived treatment failure and discontinuation of treatment. To enable evidence-based counselling of patients on realistic expectations, we determined the chance of patients with overactive bladder becoming free of a given symptom upon treatment with a muscarinic antagonist in a non-interventional setting.

METHODS

Two non-interventional studies included 1335 and 745 patients, respectively, who received 30 or 45 mg q.d. propiverine ER for 12 weeks. They were monitored for becoming free of urgency, urinary incontinence, frequency, or nocturia. Analyses were also performed in subgroups defined by basal symptom severity, age, and gender. Categorical data are shown as a percentage of the respective population. Continuous data are expressed as means or as median depending on whether the variability was considered to exhibit a normal distribution.

RESULTS

The probability of becoming symptom-free was largest for incontinence and frequency (about 50%), but lesser for urgency (about 20%) and nocturia (about 10%). Greater basal severity of a symptom reduced the chance to become free of that symptom upon treatment, but the chance to become free of incontinence and frequency was still considerable. Age and gender had only minor if any effects on the chance of becoming symptom-free. These findings are in line with those of a limited number of randomized controlled trials.

CONCLUSION

These data provide an evidence base for the counselling of patients with overactive bladder on realistic expectations of treatment outcomes. We propose that realistic expectations can lead to greater long-term adherence.

Building Robustness into Translational Research

Nonclinical studies form the basis for the decision whether to take a therapeutic candidate into the clinic. These studies need to exhibit translational robustness for both ethical and economic reasons. Key findings confirmed in multiple species have a greater chance to also occur in humans. Given the heterogeneity of patient populations, preclinical studies or at least programs comprising multiple studies need to reflect such heterogeneity, e.g., regarding strains, sex, age, and comorbidities of experimental animals. However, introducing such heterogeneity requires larger studies/programs to maintain statistical power in the face of greater variability. In addition to classic sources of bias, e.g., related to lack of randomization and concealment, translational studies face specific sources of potential bias such as that introduced by a model that may not reflect the full spectrum of underlying pathophysiology in patients, that defined by timing of treatment, or that implied in dosing decisions and interspecies differences in pharmacokinetic profiles. The balance of all these factors needs to be considered carefully for each study and program.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

An observational study of patient satisfaction with fesoterodine in the treatment of overactive bladder: effects of additional educational material

AIM

To compare the effects of additional educational material on treatment satisfaction of overactive bladder (OAB) patients treated with a muscarinic receptor antagonist.

METHODS

In an observational study of OAB patients being treated by their physician with fesoterodine for 4 months (FAKTEN study), sites were randomised to providing standard treatment or additional educational material including the SAGA tool. Patient satisfaction was assessed by three validated patient-reported outcomes including the Treatment Satisfaction Question. Because of premature discontinuation of the study, descriptive statistical analysis was performed.

RESULTS

A total of 431 and 342 patients received standard treatment or additional educational material, respectively. At study end, 76.1% [95% CI = 71.3, 80.4] of patients with standard care and 79.6% [95% CI = 74.4, 84.1] with additional SAGA tool were satisfied with treatment (primary end-point). Comparable outcomes with and without the additional educational material were also found in various patient subgroups, at the 1-month time point, and for the other patient-reported outcomes. A notable exception was the subgroup of treatment-naïve patients in which the percentage of satisfied patients was 77.2% vs. 89.5% with standard treatment and additional SAGA tool, respectively (post hoc analysis).

DISCUSSION AND CONCLUSIONS

In an observational study, most overactive bladder patients were satisfied with fesoterodine treatment. Because of the small sample size, the study does not support or refute the hypothesis that adding the SAGA tool will improve patient satisfaction with treatment. The potential effect of additional educational material in treatment-naïve patients warrants further dedicated studies.

Does concomitant diabetes affect treatment responses in overactive bladder patients?

AIMS

To compare the efficacy and tolerability of a muscarinic receptor antagonist, darifenacin, in the treatment of overactive bladder (OAB) patients with concomitant diabetes as compared with those without comorbidities.

METHODS

Post hoc exploratory analysis of a published, large, non-interventional study in OAB patients treated with darifenacin including 532 diabetics and 1315 controls. Associations of diabetes with treatment responses were evaluated by multiple regression models.

RESULTS

Diabetics (largely type 2 patients) and controls differed in baseline age, body weight, duration of OAB symptoms and presence of co-medications. However, they exhibited similar OAB symptom episode frequency and problem rating and received similar starting doses of darifenacin. Presence of diabetes was associated with a significantly smaller reduction of OAB symptoms, but the effect attributable to diabetes was small relative to the overall treatment response. The presence of diabetes was not associated with differences in tolerability.

DISCUSSION AND CONCLUSIONS

We conclude that a muscarinic receptor antagonist has comparable efficacy and tolerability in the treatment of OAB patients with and without concomitant diabetes.

Observational study on safety and tolerability of duloxetine in the treatment of female stress urinary incontinence in German routine practice

AIMS

To evaluate the safety and tolerability of duloxetine during routine clinical care in women with stress urinary incontinence (SUI) in Germany, and in particular, to identify previously unrecognized safety issues as uncommon adverse reactions, and the influence of confounding factors present in clinical practice on the safety profile of duloxetine.

METHODS

Office-based urologists, gynaecologists and primary care physicians were asked to document women newly started on treatment for moderate to severe symptoms of SUI. Six thousand eight hundred and fifty-four patients from urologist/gynaecologist practices and 5879 primary care patients were assessed. In a two-armed, observational study with parallel 12 week (urologists and gynaecologists) or 24 week (primary care physicians) design, patients were treated with duloxetine or other conservative treatment. The main outcome measure was the occurrence of adverse events (AEs).

RESULTS

Baseline characteristics differed slightly between patient groups and studies. Duloxetine doses in most patients were lower than recommended. Overall, AE frequency with duloxetine was lower than in controlled studies (15.9% (95% CI 14.9, 16.9) and 9.1% (95% CI 8.2, 10.0) in the 12 and 24 week treatment groups, respectively), but exhibited a similar qualitative spectrum. In the logistic regression models, the following factors were associated with greater AE risk: investigator specialization (gynaecologist vs. urologist and primary care physician), initial duloxetine dose (80 vs. 20 mg day(-1) ) and use of any concomitant medication. Within the 24 week study, a positive screen for depressive disorder was surprisingly common, but no case of attempted suicide was reported in either study.

CONCLUSIONS

Our results from German clinical practice show that women with SUI were often treated with duloxetine doses lower than recommended. This was associated with a low incidence of AEs. Suicide attempts were not reported.

Autonomic nervous control of the urinary bladder

The autonomic nervous system plays an important role in the regulation of the urinary bladder function. Under physiological circumstances, noradrenaline, acting mainly on β(3) -adrenoceptors in the detrusor and on α(1) (A) -adrenoceptors in the bladder outflow tract, promotes urine storage, whereas neuronally released acetylcholine acting mainly on M(3) receptors promotes bladder emptying. Under pathophysiological conditions, however, this system may change in several ways. Firstly, there may be plasticity at the levels of innervation and receptor expression and function. Secondly, non-neuronal acetylcholine synthesis and release from the urothelium may occur during the storage phase, leading to a concomitant exposure of detrusor smooth muscle, urothelium and afferent nerves to acetylcholine and noradrenaline. This can cause interactions between the adrenergic and cholinergic system, which have been studied mostly at the post-junctional smooth muscle level until now. The implications of such plasticity are being discussed.