An update on the pharmacotherapy for lower urinary tract dysfunction

Nonneurogenic female bladder outlet obstruction: Conservative and medical management

INTRODUCTION

In nonneurogenic female bladder outlet obstruction (BOO), management goals include reduction of outlet resistance to increase urinary outflow and improve bladder voiding to prevent or reduce lower and upper urinary tract (LUT and UUT) function deterioration, by correcting the underlying etiology. As significant progress has been achieved in the conservative and pharmacological management of nonneurogenic female BOO, the purpose of this article is to review and summarize the current literature.

MATERIALS AND METHODS

For this narrative review, a PubMed® search was performed by cross-referencing the keywords "female bladder outlet obstruction," "female voiding dysfunction," "conservative management," "pharmacological management," and "treatment" with various terms related to the management of female BOO. Clinical practice guidelines and landmark reviews from the most renowned experts in the field were also used.

MANAGEMENT

This review discusses and summarizes the conservative and pharmacological management of nonneurogenic female BOO based on the most relevant data currently available in the literature.

CONCLUSION

The recent advances in the understanding of underlying mechanisms involved in female BOO allow for more individualized management. Conservative and pharmacological options show interesting outcomes, particularly in the context of a functional cause of BOO. Overall, the level of evidence is still low regarding the use of conservative and pharmacological measures and more long-term data are required.

Potential role of oxidative stress in the pathogenesis of diabetic bladder dysfunction

Diabetes mellitus is a chronic metabolic disease, posing a considerable threat to global public health. Treating systemic comorbidities has been one of the greatest clinical challenges in the management of diabetes. Diabetic bladder dysfunction, characterized by detrusor overactivity during the early stage of the disease and detrusor underactivity during the late stage, is a common urological complication of diabetes. Oxidative stress is thought to trigger hyperglycaemia-dependent tissue damage in multiple organs; thus, a growing body of literature has suggested a possible link between functional changes in urothelium, muscle and the corresponding innervations. Improved understanding of the mechanisms of oxidative stress could lead to the development of novel therapeutics to restore the redox equilibrium and scavenge excessive free radicals to normalize bladder function in patients with diabetes.

Management of Urgency and Mixed Urinary Incontinence

Urinary incontinence (UI) is a prevalent disorder that significantly affects quality of life. This article reviews management of urgency and mixed UI by breaking the management algorithm down into observation, lifestyle and behavioral changes, pharmacologic therapy, and procedural management. Stress UI is best managed with mid-urethral slings and is covered in other chapters. Behavioral and pharmacologic management are equally efficacious for urgency UI, but procedural therapy is superior. Mixed UI is conventionally treated by first managing whichever UI subtype is most bothersome. The management of overflow UI is directed at its underlying etiology: detrusor underactivity or bladder outlet obstruction.

Combination phosphodiesterase type 4 inhibitor and phosphodiesterase type 5 inhibitor treatment reduces non-voiding contraction in a rat model of overactive bladder

Introduction

Current treatments for overactive bladder (OAB) are often discontinued due to side effects or lack of efficacy. The goal of this study was to determine if combining a phosphodiesterase type 4 inhibitor (PDE4i); with a type 5 inhibitor (PDE5i); would have a beneficial effect on OAB symptoms and if a reduced dose of PDE4i in combination with PDE5i could also provide a beneficial effect in OAB. We hypothesized that PDE5i and PDE4i combination treatment could be utilized to reduce non-voiding contractions and smooth muscle disruption in a rat model of OAB.

Methods

Fifty-eight age-matched Sprague-Dawley rats underwent PBOO and daily gavage with PDE4i alone (roflumilast; 1mg/kg), PDE5i alone (tadalafil;10mg/kg), high dose combination (PDE4i 1mg/kg, PDE5i 10mg/kg), low dose combination (PDE4i 0.2mg/kg, PDE5i 10mg/kg), or vehicle for 28 days. Fourteen animals underwent sham PBOO with vehicle. Rats underwent conscious and anesthetized cystometry 28 days after PBOO and were euthanized for qualitative bladder histology. One-way ANOVA on ranks with a Dunn’s post hoc test was used to indicate statistically significant differences between groups (p<0.05).

Results

Bladder & urethral weight was significantly increased after PBOO with vehicle, PDE4i alone, and PDE5i alone, but not with either combination treatment. Frequency of non-voiding contractions during both conscious and anesthetized cystometry increased significantly after PBOO with vehicle, but not after PDE4i or high dose combination treatments compared to sham PBOO. Threshold pressure for voiding was significantly decreased with high dose combination compared to vehicle. PBOO treated with PDE4i alone or high dose combination showed less bladder smooth muscle fibrosis than vehicle, PDE5i alone, or low dose combination treatments.

Conclusion

A PDE4i and PDE5i combination treatment has potential benefit in reducing OAB symptoms, but future research is needed.

Female bladder outlet obstruction: an update on diagnosis and management

PURPOSE OF REVIEW

The diagnosis and evaluation of bladder outlet obstruction (BOO) in women remains a challenging topic. The goal of this study is to review recent literature and summarize the diagnosis and management of BOO with special focus on recent progress.

RECENT FINDINGS

In recent years, numerous advances in the area of female BOO have taken place including a movement towards unified diagnostic criteria, summary of functional and anatomic causes, and exploration of potential diagnostic options.

SUMMARY

This review discusses the known diagnosis and management of female bladder outlet obstruction, yet highlights specific functional causes, new criteria available for diagnosis, and long-term results of treatment options.

Clinical implications of underactive bladder

Underactive bladder (UAB) is a common urologic condition but a complex disease that causes troublesome lower urinary tract symptoms. Currently, management of UAB remains unsatisfactory. Also, many urological diseases can be combined with UAB. In these combined cases, the treatment results may be affected by UAB component. This review focuses on the clinical implications of UAB in patients with common urologic conditions, including bladder outlet obstruction, overactive bladder syndrome and stress urinary incontinence.

A Mouse Model of Furosemide-Induced Overactive Bladder

Detailed in this unit is a mouse model of overactive bladder and urinary incontinence based on diuretic stress-induced urination. The procedure involves the use of a unique, highly sensitive, and automated urine capturing method to measure urinary latency, frequency, and void volume. Although this method was first described and validated using an anti-muscarinic drug used for treating overactive bladder, subsequent work has shown that effective non-cholinergic agents can be detected. These findings indicate good predictive value for this model regarding the possible clinical utility of test agents as treatments for overactive bladder, regardless of their site of action. © 2016 by John Wiley & Sons, Inc.

Big-conductance Ca2+-activated K+ channels in physiological and pathophysiological urinary bladder smooth muscle cells

Contraction and relaxation of urinary bladder smooth muscle cells (UBSMCs) represent the important physiological functions of the bladder. Contractile responses in UBSMCs are regulated by a number of ion channels including big-conductance Ca²⁺- activated K⁺ (BK) channels. Great progress has been made in studies of BK channels in UBSMCs. The intent of this review is to summarize recent exciting findings with respect to the functional interactions of BK channels with muscarinic receptors, ryanodine receptors (RyRs) and inositol triphosphate receptors (IP₃Rs) as well as their functional importance under normal and pathophysiological conditions. BK channels are highly expressed in UBSMCs. Activation of muscarinic M₃ receptors inhibits the BK channel activity, facilitates opening of voltage-dependent Ca²⁺ (Ca_V) channels, and thereby enhances excitability and contractility of UBSMCs. Signaling molecules and regulatory mechanisms involving RyRs and IP₃Rs have a significant effect on functions of BK channels and thereby regulate cellular responses in UBSMCs under normal and pathophysiological conditions including overactive bladders. Moreover, BK channels may represent a novel target for the treatment of bladder dysfunctions.

Clinical and urodynamic effects of baclofen in women with functional bladder outlet obstruction: Preliminary report

AIM

To investigate the efficacy and urodynamic effects of baclofen in women with functional bladder outlet obstruction.

METHODS

Between January 2011 and December 2012, women who underwent baclofen treatment for functional bladder outlet obstruction, defined as <15 mL/s maximum flow rate and >20 cmH2 O detrusor pressure at maximum flow rate, but without significant anatomic causes, were retrospectively reviewed. Urodynamic variables at baseline and after 12 weeks of treatment were compared.

RESULTS

Twenty women with functional bladder outlet obstruction underwent 12 weeks of baclofen treatment (oral baclofen 5 mg, three times daily). All patients reported improvement in voiding dysfunction symptoms after treatment, and no significant adverse effects were found on review of medical records. All patients underwent urodynamic studies after 12 weeks' treatment. Voided volume, voiding efficiency and maximum flow rate at voiding cystometry were significantly improved (mean, 273 vs. 368 mL, P = 0.002; 62.8% vs. 73.6%, P <0.001, and 10.3 vs. 11.6 mL/s, P = 0.046; respectively). Moreover, baclofen did not affect continence function, as indicated by non-significant changes in the parameters of urethral pressure profiles.

CONCLUSIONS

Oral baclofen can improve symptoms of voiding dysfunction, voided volume, voiding efficiency and maximum flow rate in women with functional bladder outlet obstruction. None of the patients experienced intolerable side-effects. Thus, oral baclofen may be used as an initial treatment for women with symptoms of voiding dysfunction.

Translational approaches to the treatment of benign urologic conditions in elderly women

PURPOSE OF REVIEW

Stress urinary incontinence, overactive bladder, interstitial cystitis/painful bladder syndrome, and underactive bladder are highly prevalent among elderly women, and have significant impact on quality of life; however, existing treatments are limited and are not always successful for all patients. Researchers are investigating a multitude of new therapies to treat these conditions. This review will summarize the recent literature on investigative therapies for these conditions.

RECENT FINDINGS

Multiple new treatments are being developed for lower urinary tract dysfunction. Some of these treatments, including balloon therapy and muscle-derived stem cells for stress urinary incontinence, could provide alternatives to existing therapies. Others require further research before being used in patients, such as pudendal nerve stimulation for overactive bladder and intravesical liposomes for drug delivery in interstitial cystitis/painful bladder syndrome.

SUMMARY

Multiple new therapies are being investigated that could provide clinicians with additional tools to treat lower urinary tract disorders in millions of elderly women.

Postmenopausal overactive bladder

Bladder storage symptoms have a severe impact on many areas as regards the quality of life including health-related, social, psychological and working functions. Pharmacotherapy of lower urinary tract stores (LUTS) has been developed to optimize neural control of the lower urinary tract in pathologic states. The bladder can be overactive or underactive. Overactive bladder (OAB) is highly prevalent and is associated with considerable morbidity, especially in aging population. Therefore, an effective treatment of OAB must result in a meaningful reduction in urinary symptoms. Pharmacotherapy for the OAB must be individualized based on the degree of bother, medication side-effect profile, concomitant comorbidities and current medication regimen. Antimuscarinic agents will continue to represent the current gold standard for the first-line pharmacological management of OAB. Alternatively to antimuscarinic therapy, β3-adrenergic receptor agonists, due to their efficacy and favorable adverse event profile, are a novel and attractive option of pharmacological treatment of overactive bladder symptoms. A combination of selective antimuscarinic and β3-adrenergic receptor agonists, agents with the different mechanism of action, gives a new treatment option for the patient with OAB according to its harms profile. A number of putative novel therapeutic agents is under clinical evaluations that may ultimately provide alternative or combination treatment options for OAB in the nearest future.

Emerging neural stimulation technologies for bladder dysfunctions

In the neural engineering field, physiological dysfunctions are approached by identifying the target nerves and providing artificial stimulation to restore the function. Neural stimulation and recording technologies play a central role in this approach, and various engineering devices and stimulation techniques have become available to the medical community. For bladder control problems, electrical stimulation has been used as one of the treatments, while only a few emerging neurotechnologies have been used to tackle these problems. In this review, we introduce some recent developments in neural stimulation technologies including microelectrode array, closed-loop neural stimulation, optical stimulation, and ultrasound stimulation.