Advancements in pharmacologic management of the overactive bladder

Acupuncture for Women with Overactive Bladder: Perspective of Traditional Chinese Medicine and Related Mechanism

Purpose

Overactive bladder (OAB) syndrome is one of the most common diseases in urology and affects quality of life. Although the current treatment for OAB is based on oral medications, there are limitations and many patients have difficulty accepting drug-induced adverse effects. This review aimed to analyze the efficacy of acupuncture and its related mechanisms and provide a preliminary therapeutic regimen.

Methods

Two authors independently searched PubMed, Embase, and Cochrane Library up to April 2022. They searched related English literature and extracted the data under a standard form based on the search strategy. Clinical trials which included OAB women with the treatment of acupuncture were included. Common acupuncture alone without other pharmacotherapy, external treatments was in the treatment group. The control interventions may include any active treatments, sham placebo, or no establishment of a control group. Outcomes included 3-day or 24-hour voiding diary, overactive bladder symptom score, etc. The Cochrane risk of bias tool was also used to assess the methodological quality of the randomized controlled trials (RCTs).

Results

We analyzed five RCTs and one comparative study on acupuncture for OAB to review and discuss the acupoint location, treatment course, and retention time based on clinical evidence and treatment ideas in traditional Chinese medicine. Additionally, we used the available evidence to reveal and discuss the acupuncture mechanisms for OAB. Acupuncture may regulate bladder function by inhibiting C-fibers, modulating nerve growth factors and reducing spontaneous contractions of the detrusor muscle.

Conclusion

Combined with the available evidence, the combination of local acupoints and distal acupoints should be necessary to consider, especially the lumbosacral acupoints, the small abdomen acupoints and the lower limb acupoints. Among them, acupuncture at SP4, CV4 and KI3 are strongly recommended. The treatment course of acupuncture should be no less than 4 weeks and maintain the frequency of acupuncture no less than once a week. The duration of each session should be no less than 20 minutes. In addition, investigations remain necessary to verify acupuncture's efficacy and precise mechanism for OAB treatment in further exploration.

Differential effects of the enantiomers of tamsulosin and tolterodine on P-glycoprotein and cytochrome P450 3A4

The pregnane X receptor (PXR) is a transcription factor regulating P-glycoprotein (P-gp; ABCB1)-mediated transport and cytochrome P450 3A4 (CYP3A4)-mediated metabolism of xenobiotics thereby affecting the pharmacokinetics of many drugs and potentially modulating clinical efficacy. Thus, pharmacokinetic drug-drug interactions can arise from PXR activation. Here, we examined whether the selective α1-adrenoreceptor blocker tamsulosin or the antagonist of muscarinic receptors tolterodine affect PXR-mediated regulation of CYP3A4 and of P-gp at the messenger RNA (mRNA) and protein level in an enantiomer-specific way. In addition, the effect of tamsulosin and tolterodine on P-gp activity was evaluated. We used quantitative real-time PCR, gene reporter assay, western blotting, rhodamine efflux assay, and calcein assay for determination of expression, activity, and inhibition of P-glycoprotein. The studied compounds significantly and concentration-dependently increased PXR activity in the ABCB1-driven luciferase-based reporter gene assay. We observed much stronger induction of ABCB1 mRNA by S-tamsulosin as compared to the R or racemic form. R or racemic form of tolterodine and R-tamsulosin concentration-dependently increased P-gp protein expression; the latter also enhanced P-gp efflux function in a rhodamine-based efflux assay. R-tamsulosin and all forms of tolderodine slightly inhibited P-gp. The effect on CYP3A4 expression followed the same pattern but was much weaker. Taken together, tamsulosin and tolterodine are demonstrated to interfere with P-gp and CYP3A4 regulation in an enantiomer-specific way.

Single compartment drug delivery

Drug design is built on the concept that key molecular targets of disease are isolated in the diseased tissue. Systemic drug administration would be sufficient for targeting in such a case. It is, however, common for enzymes or receptors that are integral to disease to be structurally similar or identical to those that play important biological roles in normal tissues of the body. Additionally, systemic administration may not lead to local drug concentrations high enough to yield disease modification because of rapid systemic metabolism or lack of sufficient partitioning into the diseased tissue compartment. This review focuses on drug delivery methods that physically target drugs to individual compartments of the body. Compartments such as the bladder, peritoneum, brain, eye and skin are often sites of disease and can sometimes be viewed as "privileged," since they intrinsically hinder partitioning of systemically administered agents. These compartments have become the focus of a wide array of procedures and devices for direct administration of drugs. We discuss the rationale behind single compartment drug delivery for each of these compartments, and give an overview of examples at different development stages, from the lab bench to phase III clinical trials to clinical practice. We approach single compartment drug delivery from both a translational and a technological perspective.

Preparation, characterization and pharmacological evaluation of tolterodine hydrogels for the treatment of overactive bladder

In this study, transdermal gel formulations for tolterodine were developed to investigate the effects of gel matrix and chemical enhancers on drug skin permeation from tolterodine hydrogels. In vitro permeation studies of tolterodine through excised mouse skin were carried out using Franz-type diffusion cells. In the optimum gel formulation, Carbopol 940 was selected as the gel matrix. Compared to gels without enhancer, tolterodine hydrogels with N-methyl pyrrolidone (NMP) showed significant enhancing effect on transdermal permeation of tolterodine (p<0.05). The results of in vitro percutaneous delivery experiment showed that the relationship of the steady accumulative percutaneous amount (Q, μg cm(-2)) of tolterodine hydrogels and time was Q4-12h=770.19t(1/2)-966.99. Tolterodine permeated at the steady-state speed of 770.19 μg cm(-2)h(-1) and its release coincided with Higuchi Equation. The pharmacokinetic properties of the optimized tolterodine formulation were studied in rabbits. The absolute bioavailability of tolterodine was 11.47%. Since the absence of hepatic first-pass metabolism, only a single active compound-tolterodine was detected in the plasma. A skin irritation study was also carried out on rabbits, and the results showed tolterodine hydrogels had no skin irritation. In the pharmacodynamic study, the significant effects of tolterodine hydrogels on the inhibition of pilocarpine-induced rat urinary bladder contraction were last to 12h, indicating that tolterodine hydrogels could produce prolonged pharmacological responses. In conclusion, tolterodine hydrogels were formulated successfully using Carbopol 940 and NMP and these results helped in finding the optimum formulation for percutaneous drug release. It is quite evident that tolterodine hydrogels may offer a possibility to avoid the first-pass effect, resulting in a single active compound of tolterodine in plasma, which may profit on the patient under the dose control and the reduction of potential adverse effect from two active compounds in the body.

Effect of weight loss on urinary incontinence in women

BACKGROUND

The purpose of this research was review the epidemiology of the association of obesity and urinary incontinence, and to summarize the published data on the effect of weight loss on urinary incontinence.

METHODS

A literature review of the association between urinary incontinence and overweight/obesity in women was performed. Case series and clinical trials reporting the effect of surgical, behavioral, and/or pharmacological weight loss on urinary incontinence are summarized.

RESULTS

Epidemiological studies demonstrate that obesity is a strong and independent risk factor for prevalent and incident urinary incontinence. There is a clear dose-response effect of weight on urinary incontinence, with each 5-unit increase in body mass index associated with a 20%-70% increase in risk of urinary incontinence. The maximum effect of weight on urinary incontinence has an odds ratio of 4-5. The odds of incident urinary incontinence over 5-10 years increase by approximately 30%-60% for each 5-unit increase in body mass index. There appears to be a stronger association between increasing weight and prevalent and incident stress incontinence (including mixed incontinence) than for urge incontinence. Weight loss studies indicate that both surgical and nonsurgical weight loss leads to significant improvements in prevalence, frequency, and/or symptoms of urinary incontinence.

CONCLUSION

Epidemiological studies document overweight and obesity as important risk factors for urinary incontinence. Weight loss by both surgical and more conservative approaches is effective in reducing urinary incontinence symptoms and should be strongly considered as a first line treatment for overweight and obese women with urinary incontinence.

Overactive bladder drugs and constipation: a meta-analysis of randomized, placebo-controlled trials

BACKGROUND

Anticholinergic drugs are commonly prescribed for symptomatic treatment of overactive bladder (OAB). While recent meta-analyses have characterized the prevalence of dry mouth among patients utilizing OAB medications, prevalence of constipation has not been systematically reviewed.

AIMS

To provide an effect measure for constipation associated with anticholinergic OAB drugs versus placebo.

METHODS

A meta-analysis of trials with darifenacin, fesoterodine, oxybutynin, solifenacin, tolterodine, and trospium was conducted. All randomized, placebo-controlled studies of anticholinergic OAB drugs published in English language and identified in Medline and Cochrane databases were considered for inclusion in this meta-analysis. Those meeting predetermined design characteristics and having sufficient duration (≥2 weeks) were included. Constipation-related data from all included studies were abstracted.

RESULTS

One hundred two English-language, randomized, placebo-controlled trials were originally identified. Thirty-seven studies were ultimately included in the analysis, involving 19,434 total subjects (12,368 treatment+7,066 placebo patients). The odds ratios for constipation compared with placebo were as follows: overall [odds ratio (OR) 2.18, 95% confidence interval (CI)=1.82-2.60], tolterodine (OR 1.36, 95% CI=1.01-1.85), darifenacin (OR 1.93, 95% CI=1.40-2.66), fesoterodine (OR 2.07, 95% CI=1.28-3.35), oxybutynin (OR 2.34, 95% CI=1.31-4.16), trospium (OR 2.93, 95% CI=2.00-4.28), and solifenacin (OR 3.02, 95% CI=2.37-3.84).

CONCLUSIONS

Our results demonstrate that patients prescribed anticholinergic OAB drugs are significantly more likely to experience constipation. Differences in muscarinic receptor affinities among individual agents may possibly account for the modest variation in constipation rates observed; however, such a determination warrants additional research.

Studies on the preparation, characterization and pharmacological evaluation of tolterodine PLGA microspheres

In this study, poly(d,l-lactide-co-glycolide) (PLGA) microspheres of tolterodine depot formulation were prepared using oil in water (o/w) method to investigate their potential pharmacokinetic and pharmacodynamic advantages over tolterodine l-tartrate tablets. Morphological studies of the microspheres showed a spherical shape and smooth surface with mean size of 50.69-83.01 microm, and the encapsulation efficiency was improved from 62.55 to 79.10% when the polymer concentration increased from 180 to 230 mg/ml. The addition of stearic or palmitic acids could significantly raise the drug entrapment efficiency but only slightly affected the in vitro release. A low initial burst followed by a proximately constant release of tolterodine was noticed in the in vitro release profiles. The in vivo study was carried out by intramuscular (i.m.) administration of tolterodine-loaded microspheres on beagle dogs, and a sustained release of drug from the PLGA microspheres was achieved until the 18th day with a low initial burst. Since the absence of hepatic first pass metabolism, only a single active compound-tolterodine was detected in the plasma. This avoided the coexistence of two active compounds in plasma in the case of oral administration of tolterodine, which may lead to a difficulty in dose control due to the different metabolic capacity of patients. In the pharmacodynamic study, the influence of tolterodine PLGA microspheres on the inhibition of carbachol-induced rat urinary bladder contraction was more significant than that of tolterodine l-tartrate tablets. There were invisible changes in rat bladder slices between tolterodine-loaded PLGA microspheres group and tolterodine l-tartrate tablets group. These results indicate that the continuous inhibition of muscarinic receptor may offer an alternative therapy of urge incontinence.

Clinical pharmacokinetics of trospium chloride

Trospium chloride, a quaternary amine with anticholinergic properties, is used for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency and urinary frequency. The pharmacokinetics of trospium chloride have been investigated in healthy volunteers, in patients with renal and hepatic impairment, and in those with symptoms of overactive bladder, after oral, intravenous and intravesical administration. After oral administration, absorption of the hydrophilic trospium chloride is slow and incomplete. Peak plasma concentrations (Cmax) of approximately 4 ng/mL are reached 4-5 hours after administration of a 20 mg immediate-release preparation. The mean bioavailability is approximately 10% and decreases by concomitant food intake (to a mean of 26% of the fasting area under the plasma concentration-time curve [AUC]). Trospium chloride displays dose proportional increases in AUC and Cmax after a single dose within the clinically relevant dose range (20-60 mg). The mean volume of distribution is approximately 350-800 L. The drug is minimally (mean approximately 10%) metabolised to spiroalcohol by hydrolysis, is 50% plasma protein bound and does not cross the blood-brain barrier. Urinary excretion of the parent compound plays a major role in the disposition of the drug, with a mean renal clearance of 29 L/h (accounting for approximately 70% of total clearance) and a mean elimination half-life ranging from 10 to 20 hours. Elimination of the drug is slowed in patients with renal insufficiency, and population pharmacokinetic modelling has demonstrated that drug clearance is correlated with serum creatinine concentration. Thus, dose reduction is needed in patients with severe renal impairment (i.e. creatinine clearance < 30 mL/min). To date, no clinically relevant pharmacokinetic drug-drug interactions have been identified; the drug does not bind to any of the drug metabolising cytochrome P450 enzymes. The pharmacokinetics of the drug are compatible with twice-daily administration. A once-daily schedule may also be appropriate, but this regimen needs formal clinical evaluation.

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

OBJECTIVE

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

SUBJECTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Nocturnal polyuria in women with overactive bladder symptoms and nocturia

OBJECTIVE

This study was undertaken to determine the prevalence of nocturnal polyuria in women complaining of nocturia and overactive bladder (OAB) symptoms and to identify clinical and health characteristics associated with nocturnal polyuria.

STUDY DESIGN

Women presenting to a urogynecology clinic with complaints of nocturia and OAB symptoms were asked to participate. They completed a health characteristic summary, 3-day voiding diary, Nordic sleep questionnaire, urinary distress inventory (UDI), and a nocturia distress visual log (NDVL). The 24-hour urine production, nighttime urine volume, and maximum bladder capacity were calculated from the bladder diary. Nocturnal polyuria was defined as production of greater than 33% of the 24-hour urine volume during an 8-hour sleep period. A histogram was performed to analyze at what age the prevalence of nocturnal polyuria increased. Women were then divided by presence or absence of nocturnal polyuria and compared by the health and clinical characteristics.

RESULTS

Fifty-five women met the qualifications and participated in the study. Average age of the cohort was 65.8 +/- 13.5 years. The risk of nocturnal polyuria increased with age 65 years or older (prevalence for age 65-74 = 0.86 [0.62-1.00]) and with white race. On the basis of the mean population values for UDI, NDVL, sleepiness scores, and insomnia scores, all women were bothered by their nocturia. Median number of nighttime voids, 24-hour urine production, maximum bladder capacity, nocturnal index, UDI, NDVL, sleepiness scores, and insomnia scores did not differ, based on presence or absence of nocturnal polyuria.

CONCLUSION

Among women complaining of nocturia and overactive bladder symptoms, age 65 years or older and white race appear to be risk factors for nocturnal polyuria.

Urinary Urgency and Frequency: What Should a Clinician Do?

Obstetrician-gynecologists often care for women with urinary symptoms of urgency and frequency. These symptoms are bothersome and treatable. Although it is rare that serious disease is causative, the clinician must be alert to ominous signs and physical findings. Most patients experience relief of their symptoms after a simple initial evaluation with appropriately directed treatment. A step-wise evaluation includes the directed history and physical, assessment of urinary habits, typically with a urinary diary, and occasionally an assessment of voiding efficiency, typically with a postvoid residual. Treatments may include myofascial therapy when trigger points are present on physical examination. Behavioral therapy and pharmaceuticals also play an important role. Persistent symptoms, hematuria, severe de novo postoperative symptoms, and ominous physical findings may warrant specialty consultation.

Medikament�se Therapie der weiblichen Harninkontinenz

Drug treatment for female urinary incontinence requires a thorough knowledge of the differential diagnosis and pathophysiology of incontinence as well as of the pharmacological agents employed. Pharmacotherapy has to be tailored to suit the incontinence subtype and should be carefully balanced according to efficacy and side effects of the drug. Women with urge incontinence require treatment that relaxes or desensitizes the bladder (antimuscarinics, estrogens, alpha-blockers, beta-mimetics, botulinum toxin A, resiniferatoxin, vinpocetine), whereas patients with stress incontinence need stimulation and strengthening of the pelvic floor and external sphincter (alpha-mimetics, estrogens, duloxetine). Females with overflow incontinence need reduction of outflow resistance (baclofen, alpha-blockers, intrasphincteric botulinum toxin A) and/or improvement of bladder contractility (parasympathomimetics). If nocturia or nocturnal incontinence are the major complaints, control of diuresis is obtained by administration of the ADH analogue desmopressin. Future developments will help to further optimize the pharmacological therapy for female urinary incontinence.

Confusion about measuring central nervous system effects

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

Canadian economic comparison of extended-release oxybutynin and immediate-release tolterodine in the treatment of overactive bladder

BACKGROUND

Overactive bladder (OAB) is a condition characterized by urgency, increased frequency of micturition, or urge incontinence. It affects a considerable segment of the population, particularly with increasing age. Pharmacotherapy is one of the most common approaches to the treatment of OAB.

OBJECTIVE

This article describes the development and results of a model comparing health-economic outcomes for the new extended-release (XL) formulation of oxybutynin and immediate-release (IR) tolterodine in a population of community-dwelling Canadian adults with OAB.

METHODS

A Markov model was developed to compare health-economic outcomes over the course of 1 year. Effectiveness and treatment-persistence data were derived from the OBJECT (Overactive Bladder: Judging Effective Control and Treatment) trial, a 3-month comparison of oxybutynin XL 10 mg and tolterodine IR 4 mg, and were used, together with data from the literature (identified through a MEDLINE search of articles published between 1990 and 2003), to project outcomes beyond the trial period. Severity-specific cost profiles for incontinence were developed. In the principal analyses, cost items were limited to drug therapy, physician visits, use of pads or other protection, and laundry costs. Costs are reported in 2002 Canadian dollars.

RESULTS

Costs after 1 year were estimated to be an average of $32 less per patient for oxybutynin XL compared with tolterodine IR, and 3.1 additional patients in every 100 who received oxybutynin XL were expected to attain complete continence compared with those who received tolterodine. During the course of 1 year, patients receiving oxybutynin XL were expected to have a mean 16.5 additional incontinence-free days compared with those receiving tolterodine IR. The results were sensitive to relative drug prices. In the other sensitivity analyses, however, oxybutyrin XL maintained its advantage over a wide range of inputs.

CONCLUSION

The results of these analyses suggest that when priced equivalently, oxybutynin XL would reduce costs and provide better results than tolterodine IR over 1 year of treatment.

Trospium chloride: A quaternary amine with unique pharmacologic properties

The mainstay of pharmacologic treatment of overactive bladder is anticholinergic therapy. Cholinergic blockade is efficacious in decreasing the symptoms of urgency, frequency, and urge incontinence, but also is associated with undesirable side effects such as dry mouth, blurred vision, constipation, and central nervous system side effects. The property of anticholinergic agents that has been associated with increased efficacy and tolerability is receptor specificity. The safety of anticholinergic agents has been associated with the pharmacokinetics, metabolism, protein binding, and ability to penetrate the blood brain barrier. Trospium chloride, available in Europe for more than 20 years and under review by the US Food and Drug Administration for the treatment of overactive bladder, is a quaternary amine that is minimally metabolized, not highly protein-bound, and theoretically should not cross the blood brain barrier. Some of the characteristics of this unique anticholinergic agent are reviewed in this article and the relative contributions of these factors are discussed.

New perspectives on the overactive bladder: pharmacokinetics and bioavailability

In the United States alone, approximately 17 million men and women have symptoms of overactive bladder (OAB). For many years, oxybutynin was the drug of choice for treating OAB. Although it provided effective treatment, multiple daily doses were required, and adverse events, such as dry mouth and constipation, were decided drawbacks. Controlled drug delivery systems seen in commercially available OAB formulations alter the pharmacokinetics of antimuscarinic medications in ways that maintain efficacy and allow once-daily dosing and reduction of adverse events. In the future, OAB medications will not only incorporate new chemical entities, such as the S-enantiomer of oxybutynin, but will also use novel drug delivery technologies, including transdermal patches and bladder implants.

Pharmacologic treatment for detrusor overactivity

Recent pharmacologic treatment for detrusor overactivity has resulted in more favorable side effect profiles, not only because of the use of different drug delivery systems for older drugs but perhaps also due to the improved bladder selectivity of newer antimuscarinic agents. These developments translate into higher patient compliance and better long-term results with the newer agents over generic immediate-release oxybutynin for the treatment of the overactive bladder.