Combined intravesical and oral oxybutynin chloride in adult patients with spinal cord injury

The Management of Lower Urinary Tract Dysfunction in Multiple Sclerosis

PURPOSE OF REVIEW

Multiple sclerosis (MS) is the most frequent neuroinflammatory disease of the central nervous system and is commonly associated with lower urinary tract (LUT) dysfunction. As a consequence, health-related quality of life is often impaired and the upper urinary tract might be at risk for damage. The aim of this review is to give an overview of current treatment options for LUT dysfunction in patients with MS.

RECENT FINDINGS

The treatment is tailored to the type of dysfunction-storage or voiding dysfunction-beginning with conservative treatment options and ending with invasive therapies and surgery. Additionally, alternative options, e.g., different intravesical therapies or cannabinoids, have been evaluated in recent years with promising results. Current available therapies offer different possible treatments for LUT dysfunction in patients with MS. They address either voiding or storage dysfunction and therefore ameliorate LUT symptoms improve quality of life and protect the upper urinary tract.

An integrative review of standardized clinical evaluation tool utilization in anticholinergic drug trials for neurogenic lower urinary tract dysfunction

STUDY DESIGN

To review prospective and randomized trials studying anticholinergic therapy for neurogenic bladder in SCI to identify whether trials included standardized clinical evaluation tools and reporting measures now recognized to enhance clinical trial data.

METHODS

A systematic search via EMBASE, MEDLINE, CENTRAL, CINAHL (Cumulative Index to Nursing and Allied Health Literature), HTA (Health Technology Assessment), CMR (Comprehensive Microbial Resource), HAPI (Health and Psychosocial Instruments) and PsycINFO using the key term spinal cord injury crossed with oxybutynin, tolterodine, darifenacin, solifenacin, fesoterodine, trospium chloride, propiverine, propantheline and anticholinergic(s) for 1946-2015 inclusive. We then collated whether standardized clinical tools, measures and descriptors were used within each study identified: American Spine Injury Association (ASIA) impairment scale; symptom scores validated in SCI; technical methodology for urodynamics/video urodynamics; urinary diaries; and standardized urologic terminology.

RESULTS

A total of 1225 entries with 610 unique articles were identified, 14 randomized and 16 prospective studies. In 6/30 the population comprised SCI patients with neurogenic bladder alone; the remainder included mixed neurogenic etiologies. Classification using the ASIA impairment scale was used in <10% of studies; none used symptom scores validated in SCI; <50% reported urodynamic test methodology fully, incorporated urinary diaries or used International Continence Society Standardization Subcommittee urinary tract terminology.

CONCLUSION

Integrative review of trials from 1946 to 2015 identified infrequent use of standardized clinical evaluation tools and reporting measures. Data from future trials evaluating therapies for neurogenic bladder would likely be more applicable to specific SCI patients if current standardized classification and descriptors now available were used consistently: for example, the ASIA scale, symptom scores validated in SCI, standardized urodynamic methodology, urinary diaries and urinary tract terminology. Studies recruiting SCI patients exclusively would also provide additional benefit.

Neurogenic detrusor overactivity in adults: a review on efficacy, tolerability and safety of oral antimuscarinics

OBJECTIVES

This review analyzed efficacy, tolerability and safety of oral antimuscarinic (AM) drugs in adults suffering from neurogenic detrusor overactivity (NDO).

METHODS

A comprehensive search of major literature bases was conducted to identify all references.

RESULTS

Thirty studies, thereof 16 randomized controlled trials (RCT), enrolling 1479 patients were identified and included in the review. Results were grouped in dose-finding, placebo- and active-controlled, flexible dose and combined high-dose AM drugs, and various studies. Key urodynamic outcome parameters, such as maximum detrusor pressure and maximum cystometric bladder capacity, demonstrated the efficacy of AM in NDO, following 2-3 weeks of treatment. Contrary to idiopathic detrusor overactivity (IDO), no placebo effects manifested. Other important parameters, such as impact on the upper urinary tract function and morphology, issues of continence, post-void residual urine, catheterisation, urinary tract infections and quality of life, were investigated to a limited extent only. Incidence rates of adverse events were comparable for NDO and IDO. Most of the studies, especially RCT, were undertaken with oxybutynin immediate release (IR), trospium chloride IR, propiverine IR and propiverine extended release. In NDO, these drugs are best investigated.

CONCLUSIONS

AM drugs are effective in NDO, they normalize the intravesical pressure and increase cystometric bladder capacity. However, other important parameters are not adequately investigated so far and should be recognized in future studies.

Effect of repeated detrusor onabotulinumtoxinA injections on bladder and renal function in patients with chronic spinal cord injuries

AIMS

To investigate the therapeutic effects of repeated detrusor onabotulinumtoxinA injections on urinary incontinence and renal function in patients with chronic spinal cord injuries (SCI).

METHODS

Patients with suprasacral SCI were enrolled. OnabotulinumtoxinA 200  U detrusor injections were repeated every 6 months for four times. Patients were instructed to perform clean intermittent catheterization during the treatment and follow-up periods. Videourodynamic study and 99mTc-DTPA renal scanning for glomerular filtration rate (GFR) were performed at screening and every 3 months to assess the therapeutic effects on bladder and renal function. Quality of life was measured by the UDI-6, IIQ-7, and self-assessed QoL indices. Adverse events were also recorded.

RESULTS

A total of 33 patients completed the study, 30 had improvement in incontinence grade (n = 18) or became completely dry (n = 12) after initial and subsequent onabotulinumtoxinA injections. Mean bladder capacity increased from 207  ±  111 to 412  ±  33  ml and mean detrusor pressure decreased from 39.8  ±  21.7 to 20.6  ±  19.1  cmH(2) O (all P < 0.05). However, the mean GFR decreased from 93.4  ±  20.4 to 83.5 ±  24  ml/min (P = 0.028). A significant reduction in GFR was noted in patients with bladder compliance that increased by <10  cmH(2) O (P = 0.002) and in patients with Pdet decreased by <10  cmH(2) O after treatment (P = 0.036). All 30 patients with improvement in incontinence grade satisfied with treatment result.

CONCLUSION

This pilot study revealed that repeated detrusor injections of 200  U onabotulinumtoxinA could reduce incontinence grade, increase bladder capacity, and decrease intravesical pressure but this study did not demonstrate an improvement in GFR over a 24-month period in patients with chronic SCI.

Managing the urinary tract in spinal cord injury

This review sets out to provide an overview of the author's approach to the management of the urinary tract in the patient who has suffered from an injury to their spinal cord. Emphasis is given to the need to understand the fundamental pathophysiological patterns that are seen with injuries that involve the sacral segments of the cord (the conus) and those that spare the conus but interrupt communication between the sacral parasympathetic and somatic centers and the brain (supraconal lesions). The importance of patient participation in management decisions is highlighted by considering the different ways in which the urinary tract can be managed and how the clinician needs to try to meet patient expectations and requirements while establishing safe urological management. Finally, consideration is given to the importance of establishing an appropriate follow up regime and managing urinary tract complications effectively.

Pharmacologic therapy for the neurogenic bladder

This article is a review of the current and past literature on medical management of the neurogenic bladder, with a particular focus on spinal cord injury and multiple sclerosis. The use of antimuscarinics, αα-blocker, and tricyclic antidepressants and their combined use are discussed along with new therapies in human and animal trials.

Efficacy of combined oral-intravesical oxybutynin hydrochloride treatment for patients with overactive detrusors and indwelling urethral catheters

The purpose of this article is to investigate the efficacy of intravesical oxybutynin hydrochloride (OH) to treat patients with overactive detrusors who are unresponsive to oral anticholinergic therapy alone. Twenty-five patients who were treated with oral OH for overactive detrusor (but who did not respond to treatment and were using indwelling urethral catheters) were given intravesical OH without changing oral treatment. Pre- and posttreatment bladder capacities were compared in urodynamic studies. The study showed that positive clinical results can be achieved with combined oral and intravesical OH treatments in patients with overactive detrusors who had indwelling urethral catheters because of severely reduced bladder capacity. However, a significant number of patients discontinued this treatment because of infection and difficulty in performing the procedure. Clinicians and rehabilitation nurses should provide education and support to eliminate these problems. In addition, the development of single-use standard sterile OH preparations for intravesical applications may increase the efficacy of the method.

Contemporary role of suprapubic cystostomy in treatment of neuropathic bladder dysfunction in spinal cord injured patients

BACKGROUND

The management of neuropathic bladder dysfunction secondary to spinal cord injury is controversial. With the introduction of clean intermittent catheterization (CIC) and anti-cholinergic medication, urinary tract deterioration in this population has declined. Nevertheless, this strategy is problematic for patients who are unable to perform CIC. Suprapubic cystostomy (SPC) is widely viewed as a secondary option, which has a high satisfaction rating among patients, with acceptable clinical efficacy. Despite early reports of long-term renal and bladder complications, recent evidence has demonstrated that improved anti-cholinergic pharmacotherapy and bladder maintenance strategies can enhance SPC efficacy, with diminished morbidity. We set out to review the current literature on SPC in the neuropathic bladder setting and to clarify future management direction.

MATERIALS

This investigation consisted of a literature search of the MEDLINE and PUBMED databases. Inclusion criteria were related to SPC, indwelling catheterization, urodynamics, spinal cord injury and bladder dysfunction. Our analysis comprised 56 studies, including retrospective analyses and case reports. Investigations regarding surgical technique as well as short and long-term efficacy were also included.

RESULTS

Early studies reported accelerated renal deterioration and lower urinary tract complications, including stones, recurrent infections and blocked catheters. Procedural complications were generally rare. In contrast, recent investigations, in which patients were managed with anti-cholinergics, frequent catheter changes and bladder washing, and volume maintenance procedures demonstrated similar morbidity profiles to CIC.

Current and emerging investigational medical therapies for the treatment of overactive bladder

Overactive bladder (OAB) is a chronic distressing condition characterised by urinary urgency with or without urge incontinence, usually with frequency (voiding at least eight times daily) and nocturia. It affects millions of people worldwide independent of age, sex and race. The prevalence increases with age and is relatively higher in women compared with men. The treatment of OAB is aimed at reducing the debilitating symptoms so as to improve the overall quality of life for patients. Anticholinergic agents targeting the muscarinic receptors in the bladder represent the mainstay of pharmacotherapy for the treatment of OAB. Besides their status as the current standard of care, use of antimuscarinic drugs is limited by certain side effects, particularly dry mouth and constipation; therefore, various attempts have been made to improve the organ selectivity of these drugs to overcome the side effects. These include the development of new antimuscarinic agents with structural modifications and the use of innovative drug delivery methods. The advancement in the drug delivery systems extends to the long-term therapeutic efficacy with improved tolerability and patient compliance; however, future prospective therapies are aimed at novel targets with novel mechanisms of action, including beta3-adrenoceptor agonists, K+ channel openers, 5-HT modulators and botulinum toxin, which are currently under different stages of clinical development. Among other investigational therapies, neurokinin receptor antagonists, alpha-adrenoceptor antagonists, nerve growth factor inhibitors, gene therapy and stem cell-based therapies are of considerable interest. The future for the development of new modalities for the treatment of OAB looks promising.

Pharmacotherapy for Neurogenic Detrusor Overactivity

Chancellor MB, Anderson RU, Boone TB: Pharmacotherapy for neurogenic detrusor overactivity. Am J Phys Med Rehabil 2006;85:536-545. Patients with neurogenic detrusor overactivity are a heterogeneous group with voiding dysfunction secondary to neurologic injury or disease. The neurogenic detrusor overactivity syndrome, which may include urinary frequency, urgency, and incontinence, frequently contributes to a loss of independence, or even institutionalization. Urodynamic assessment provides the best method of quantifying and classifying neurogenic detrusor overactivity dysfunction in patients with primary diagnoses as diverse as Parkinson's disease, cerebral palsy, multiple sclerosis, spinal cord injury, and spina bifida. For many patients, management of urinary symptoms includes pharmacotherapy with an anticholinergic agent. Several novel approaches to managing neurogenic detrusor overactivity, including intravesical instillation of anticholinergic agents, vanilloids, and neurotoxins, are being investigated. For most patients, however, flexible dosing with an anticholinergic agent, with clean intermittent catheterization when indicated, has been shown to reduce the risks of urologic complications, improve levels of continence, and enhance patient quality of life in both children and adults.

The overactive bladder: review of current pharmacotherapy in adults. Part 1: pathophysiology and anticholinergic therapy

Overactive bladder is a syndrome characterised by urinary urgency, with or without urge incontinence, and usually with frequency and nocturia. It affects millions of people of all ages worldwide and causes significant morbidity, especially in terms of health-related quality of life. It poses a huge economic burden on health resources. Managing such patients involves a thorough history, physical examination and the use of pertinent investigations before the initiation of treatment. Therapy consists of lifestyle changes, bladder training, anticholinergics, second-line agents such as resiniferatoxin instillation or botulinum toxin injections into the bladder in refractory cases and, finally, in intractable cases, surgery. In the first part of this review of pharmacotherapy for the treatment of this condition, the focus is on the pathophysiological factors potentially involved in overactive bladder and covers the wide range of currently available first-line anticholinergic agents. Treatment algorithms are suggested on the basis of current literature.

Transplantation of neuronal and glial restricted precursors into contused spinal cord improves bladder and motor functions, decreases thermal hypersensitivity, and modifies intraspinal circuitry

Transplanting neuronal and glial restricted precursors (NRP/GRP) into a midthoracic injury 9 d after contusion improved bladder and motor function, diminished thermal hypersensitivity, and modified lumbosacral circuitry compared with operated controls (OP-controls). Histological analysis showed that NRP/GRP survived, filled the lesion site, differentiated into neurons and glia, and migrated selectively. Volume of spinal cord spared was increased in NRP/GRP recipients, suggesting local protection. Bladder areflexia developed in both operated groups, but NRP/GRP recipients exhibited an accelerated recovery, with decreased micturition pressure and fewer episodes of detrusor hyperreflexia. Because noradrenergic receptors proliferate after spinal injury and descending noradrenergic pathways contribute to regulation of bladder control, we examined the effects of administering an alpha-1A-adrenergic antagonist, Tamsulosin, on urodynamics. This improved all cystometric parameters in both operated groups, and micturition pressure in NRP/GRP rats recovered to normal levels. Both operated groups initially showed increased sensitivity to a thermal stimulus applied to the tail; the NRP/GRP rats showed significant improvement over time. NRP/GRP grafts also produced greater recovery of hindlimb function in several tests, although both groups showed persistent and similar deficits in locomotion on a grid. Because bladder, hindlimb, and tail sensory and motor functions are organized through lumbosacral cord, we examined descending and primary afferent projections at L6-S1. The density of serotonergic, noradrenergic, and corticotrophin releasing factor-positive fibers increased in the NRP/GRP group compared with OP-controls, suggesting some sparing and/or sprouting of these modulatory pathways. Immunocytochemical staining density of dorsal root axons in the dorsal horn increased in the OP-controls but appeared normal in the NRP/GRP group. Synaptophysin immunoreactivity in the lumbosacral dorsal horn was similar among groups, consistent with restoration of synaptic density in both groups of operated animals but by different pathways. We suggest that local protection provided by NRP/GRP resulted in increased sparing/sprouting of descending pathways, which prevented sprouting by dorsal root axons, and that this modification in lumbosacral circuitry contributes to the recovery of function.

Plasticity in the injured spinal cord: can we use it to advantage to reestablish effective bladder voiding and continence?

Micturition is coordinated at the level of the spinal cord and the brainstem. Spinal cord injury therefore directly interrupts spinal neuronal pathways to the brainstem and results in bladder areflexia. Some time after injury, however, dyssynergic bladder and sphincter function emerges. The changes mediating the appearance of bladder function after spinal cord injury are currently unknown. Primary afferent neurons have been shown to sprout in response to spinal cord injury. Sprouting primary afferents have been linked to the pathophysiology of centrally manifested disorders, such as autonomic dysreflexia and neuropathic pain. It is proposed that sprouting of bladder primary afferents contributes to disordered bladder functioning after spinal cord injury. During development of the central nervous system, the levels of specific neuronal growth-promoting and guidance molecules are high. After spinal cord injury, some of these molecules are upregulated in the bladder and spinal cord, suggesting that axonal outgrowth is occurring. Sprouting in lumbosacral spinal cord is likely not restricted to neurons involved in the micturition reflex. Furthermore, sprouting of some afferents may be contributing to bladder function after injury, whereas sprouting of others might be hindering emergence of function. Thus selective manipulation of sprouting targeting afferents that are contributing to emergence of bladder function after injury is critical. Further research regarding the role that neuronal sprouting plays in the emergence of bladder function may contribute to improved treatment of bladder dyssynergia after spinal cord injury.

Intravesical Therapy for Overactive Bladder

Overactive bladder and urgency incontinence are common conditions generally treated with oral anticholinergic therapy. Despite the development of new antimuscarinic agents, many patients do not tolerate or fail to respond to oral therapy. Intravesical instillation therapy can provide an alternative method of managing bladder overactivity. Intravesical instillation of anticholinergics such as oxybutynin and atropine can achieve cholinergic blockade without producing systemic side effects. Botulinum A toxin injected directly into the detrusor has been shown in preliminary studies to increase bladder capacity and decrease uncontrolled bladder contractility for up to 6 months. Intravesical local anesthetics such as lidocaine and bupivacaine block the conduction of unmyelinated C fibers and when administered into the bladder, lead to an increase in functional bladder capacity. Intravesical capsaicin and resiniferatoxin also affect afferent innervation by blocking C-fiber afferents, leading to decreased bladder contractility and increased bladder capacity. Intravesical instillation therapy can provide an alternative treatment for the management of overactive bladder.

Transplants of fibroblasts expressing BDNF and NT-3 promote recovery of bladder and hindlimb function following spinal contusion injury in rats

We examined whether fibroblasts, genetically modified to express BDNF and NT-3 (Fb-BDNF/NT3) and transplanted into a thoracic spinal injury site, would enhance recovery of bladder function and whether this treatment would be associated with reorganization of lumbosacral spinal circuits implicated in bladder function. Rats received modified-moderate contusion injuries at T8/9, and 9 days later, Fb-BDNF/NT3 or unmodified fibroblasts (OP-controls) were delivered into the cord. Fb-BDNF/NT3 rats recovered from areflexic bladder earlier, showed decreased micturition pressure and fewer episodes of detrusor hyperreflexia, compared to OP-controls. There were also improvements in hindlimb function in the Fb-BDNF/NT3 group although locomotion on a more challenging substrate (grid) and tail withdrawal latency in response to a thermal stimulus showed persisting deficits, little recovery, and no differences between the groups. Immunocytochemistry at L6-S1 revealed changes in density of afferent and descending projections to L6-S1 cord. The density of small dorsal root axons increased in the superficial layers of the dorsal horn in OP-controls but not in Fb-BDNF/NT3, suggesting sprouting of primary afferents following injury that was inhibited by Fb-BDNF/NT-3. In contrast, the trophic factor secreting transplants stimulated sprouting and/or sparing of descending modulatory pathways projecting to the lumbosacral spinal cord. No differences in synaptophysin immunoreactivity were seen in the dorsal horn which suggested that synaptic density was similar but achieved by sprouting of different systems in the two operated groups. Fb-BDNF/NT3 transplanted into injured spinal cord thus improved both bladder and hindlimb function, and this was associated with reorganization of spinal circuitry.

Oxybutynin for treatment of urge urinary incontinence and overactive bladder: an updated review

Urge urinary incontinence (UUI) and overactive bladder are common conditions often associated with profound impairment of the health and quality of life of the patient. Antimuscarinic medications have been the mainstay of treatment for these disorders. Oxybutynin hydrochloride, one of the most widely used antimuscarinic agents, has attracted considerable interest from both clinicians and pharmacologists over the last three decades. Although efficacy of this drug has been proven to be high, its use is limited by antimuscarinic adverse effects, possibly related to its active metabolite N-desethyloxybutynin (N-DEO). The extended-release form of oxybutynin uses a push-pull osmotic release system which has significantly improved its tolerability and safety profile. A transdermal transport system has also been developed, bypassing the first-pass metabolism in the liver and gut. This system is associated with significant reduction in the production of the primary metabolite and additional improvement in the tolerability profile of the drug. Intravesical instillation of oxybutynin has been reported although the efficacy and safety of this delivery system has yet to be determined. This article comprehensively reviews the contemporary literature on the pharmacology, clinical efficacy and adverse reactions of oxybutynin in its various delivery forms, and compares them to other frequently used medications for UUI and overactive bladder.

Intravesical therapy options for neurogenic detrusor overactivity

STUDY DESIGN

Review article.

SETTING

Neuro-Urology, Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland.

OBJECTIVES

This review considers intravesical treatment options of neurogenic detrusor overactivity and discusses the underlying mechanism of action, clinical safety and efficacy, and the future trends.

METHODS

The available literature was reviewed using medline services.

RESULTS

Oral anticholinergic drugs are widely used to treat detrusor overactivity, but they are ineffective in some patients or cause systemic side effects such as blurred vision or dry mouth. As an alternative, topical therapy strategies have been suggested to achieve a profound inhibition of the overactive detrusor and to avoid high systemic drug levels. Currently available intravesical treatment options either act on the afferent arc of the reflex such as local anaesthetics or vanilloids or on the efferent cholinergic transmission to the detrusor muscle such as intravesical oxybutynin or botulinum toxin. Although an established and effective therapy, intravesical oxybutynin is not widely used. Evidence for clinical significance of intravesical atropine and local anaesthetic is missing. Intravesical capsaicin has been shown to improve clinical and urodynamic parameters, but cause pain in some patients. The intravesical instillation of resiniferatoxin and the injection of botulinum-A toxin into the detrusor muscle are promising new options; however, randomised placebo-controlled studies to prove their safety and efficacy are still missing.

CONCLUSION

Intravesical treatment strategies in patients with neurogenic detrusor overactivity may provide alternatives to established therapies such as oral anticholinergics. The selectivity of the intravesical treatment and the reduction or even the absence of side effects are major advantages of this topical approach.

Detrusor overactivity in spina bifida: How long does it need to be treated?

AIMS

To determine whether a lasting therapeutic effect can be expected from long-term antimuscarinic therapy for neurogenic detrusor overactivity in spina bifida and to answer the question whether detrusor overactivity in spina bifida children with detrusor/sphincter dyssynergia is primarily based on the neuropathy or, in part, can be a secondary detrusor reaction to the functional urethral obstruction.

METHODS

Fifteen spina bifida patients, aged between 1 and 12 years, all on a regime of clean intermittent catheterisation (CIC) and oxybutynin since shortly after birth, underwent three consecutive urodynamic studies (UDS). One prestudy UDS for treatment control, one UDS after withdrawal of oxybutynin for 3-5 days and one UDS after reinstallment of oxybutynin treatment. Urodynamic results were compared concerning detrusor overactivity, cystometric bladder capacity, and compliance.

RESULTS

Detrusor overactivity was seen in two patients on the prestudy UDS. After several days of withdrawal of oxybutynin overactivity was seen in 11 patients. After oxybutynin withdrawal, bladder compliance was within safe margins for two patients only, after reinstallment, safe vesical pressures were seen in 11 patients.

CONCLUSION

The functional obstruction due to detrusor/sphincter dyssynergia has been by-passed chronically in all these children by CIC and oxybutynin. Due to the fact that detrusor overactivity recurs immediately after withdrawal of medication after long-term treatment with oxybutynin, one can conclude that there is no long-lasting therapeutic effect of pharmacological suppression. This suggests that in children with detrusor/sphincter dyssynergia, detrusor overactivity is primarily of neuropathic origin.

Botulinum toxin type A may improve bladder function in a rat chemical cystitis model

The purpose of this study was to investigate the effect of botulinum toxin type A on bladder function and histology in a rat chemical cystitis model. The study included 41 female Sprague-Dawley rats with chemical cystitis induced by intravesical instillation of hydrochloric acid. The acid instillation was repeated monthly to maintain chronic inflammation. The treatment group (n=21) received 2-3 units of botulinum toxin type A injected into the bladder detrusor at the 3, 6, 9 and 12 o'clock positions, and the control group (n=20) underwent saline injection into the bladder detrusor at the same positions. Urodynamic studies were performed in all rats before the treatment and at death. The rats were killed at 1 week, 2 weeks, 1 month and 2 months after treatment. The bladders were removed and examined histologically for mast cells and inflammatory changes. The cystometric findings showed that, at the beginning and end of the experiment, the increases in the maximum bladder capacity and compliance were significantly higher in the treatment group than in the control group (P=0.000 and P=0.025, respectively). The histological studies revealed similar mast cell counts and leukocyte infiltration for the treatment and control groups. In conclusion, in this rat chemical cystitis model, botulinum toxin type A injected into the bladder detrusor led to a functional improvement. Thus, botulinum toxin type A injection may be an alternative, minimally invasive choice to other surgical treatment options in the treatment of a chronic inflammatory condition to improve deteriorated bladder function.

Current and future pharmacological treatment for overactive bladder

PURPOSE

Urinary incontinence and overactive bladder are important and common conditions that have received little general medical attention. We reviewed the magnitude and impact of these conditions, and discuss pharmacotherapy as well as new drugs under investigation.

MATERIALS AND METHODS

The main emphasis of this review is pharmacological therapy for the bladder. We discuss currently available agents, drugs under development and pharmacological targets that would be suitable targets for treating overactive bladder. Drugs such as duloxetine that target not bladder smooth muscle, but rather central nervous system control of the micturition reflex are undergoing clinical trials. We also discuss intravesical therapy and alternative drug delivery methods, such as intravesical capsaicin and botulinum toxin, with special emphasis on approaches to modulate bladder afferent nerve function for preventing overactive bladder.

RESULTS

There are many advantages to advanced drug delivery systems, including long-term therapeutic efficacy, decreased side effects and improved patient compliance. Future speculation such as gene therapy holds great promise for overactive bladder because it is possible to access all genitourinary organs via endoscopy and other minimally invasive techniques that are ideally suited for gene therapy.

CONCLUSIONS

Traditional anticholinergic therapies are limited in their effectiveness. There is great hope for future research regarding voiding dysfunction and urinary incontinence through a focus on afferent nerve intervention for preventing overactive bladder.

Absorption of oxybutynin from vaginal inserts: drug blood levels and the response of the rabbit bladder

OBJECTIVES

Oxybutynin has been used for treatment of urge urinary incontinence for more than 20 years. However, one of the major problems with its use is uncomfortable anticholinergic side effects that can lead to discontinuation of treatment. Alternative forms of drug administration may reduce side effects and thus improve patient compliance.

METHODS

A cylinder-shaped, curved silicone elastomer insert containing oxybutynin was anchored in the vagina of female rabbits. The inserts were designed to release oxybutynin at rates of 0.5, 1.0, and 5.0 mg/day, respectively. Blood drug and metabolite levels were monitored for 1 to 7 days and cystometry was carried out after 7 days of treatment.

RESULTS

There was a consistent dose-dependent absorption of the oxybutynin resulting in stable plasma concentrations by 3 days. Levels of N-desethyloxybutynin, the active metabolite that is thought to be responsible for side effects, were less than 1.0 ng/mL in all groups. The cystometrograms showed a decrease in the detrusor pressures for the higher oxybutynin groups and a dose-dependent decrease in micturition pressure. The vaginal wall in contact with the insert showed no irritation.

CONCLUSIONS

The inserts produced stable blood levels and released sufficient amounts of oxybutynin to have measurable effects on the bladder. There was no irritating effect of the insert on the vaginal wall after a 1-week treatment. Vaginal inserts containing oxybutynin may be an interesting alternative method for the chronic delivery of oxybutynin.

Pharmacologic and potential biologic interventions to restore bladder function after spinal cord injury

Spinal cord injury disrupts voluntary control of voiding and the normal reflex pathways that coordinate bladder and urethral sphincter function. The present review addresses studies in animals and humans that have evaluated various therapeutic approaches for normalizing lower urinary tract function after spinal cord injury.