Pharmacokinetics and clinical effects of oxybutynin in geriatric patients

Safety and efficacy of oxybutynin in patients with hyperhidrosis: systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Sweating is a physiologic mechanism of human thermoregulation. Hyperhidrosis is defined as a somatic disorder where the sweating is exaggerated in an exact area because the sweat glands are hyperfunctioning. It negatively affects the quality of life of the patients. We aim to investigate patient satisfaction and the effectiveness of oxybutynin in treating hyperhidrosis.

METHODS

We prospectively registered the protocol of this systematic review and meta-analysis on PROSPERO (CRD 42022342667). This systematic review and meta-analysis were reported according to the PRISMA statement guidelines. We searched three electronic databases (PubMed, Scopus, Web of Science) from inception until June 2, 2022, using MeSH terms. We include studies comparing patients with hyperhidrosis who received oxybutynin or a placebo. We assessed the risk of bias using the Cochrane risk of bias assessment tool (ROB2) for randomized controlled trials. The risk ratio was calculated for categorical variables, and the mean difference was calculated for continuous variables using the random effect model with 95% confidence intervals (CI).

RESULTS

Six studies were included in the meta-analysis, with a total of 293 patients. In all studies, patients were assigned to receive either Oxybutynin or Placebo. Oxybutynin represented an HDSS improvement (RR = 1.68 95% CI [1.21, 2.33], p = 0.002). It also can improve the quality of life. There is no difference between oxybutynin and placebo regarding dry mouth (RR = 1.68 95% CI [1.21, 2.33], p = 0.002).

CONCLUSION

Our study suggests that using oxybutynin as a treatment for hyperhidrosis is significant and needs to be highlighted for clinicians. However, more clinical trials are needed to grasp the optimum benefit.

Treating Lower Urinary Tract Symptoms in Older Adults: Intravesical Options

This article provides an overview of the diagnosis and the treatment of lower urinary tract symptoms in older adults complicated by the neurodegenerative changes in the micturition reflex and further confounded by age-related decline in hepatic and renal clearance raising the propensity of adverse drug reactions. The first-line drug treatment for lower urinary tract symptoms, orally administered antimuscarinics, fails to reach the equilibrium dissociation constant of muscarinic receptors even at their maximum plasma concentration and tends to evoke a half-maximal response at a muscarinic receptor occupancy of just 0.206% in the bladder with a minimal difference from exocrine glands, which raises the adverse drug reaction risk. On the contrary, intravesical antimuscarinics are instilled at concentrations 1000-fold higher than the oral maximum plasma concentration and the equilibrium dissociation constant erects a downhill concentration gradient that drives passive diffusion and achieves a mucosal concentration around ten-fold lower than the instilled concentration for a long-lasting occupation of muscarinic receptors in mucosa and sensory nerves. A high local concentration of antimuscarinics in the bladder triggers alternative mechanisms of action and is supposed to engage retrograde transport to nerve cell bodies for neuroplastic changes that underlie a long-lasting therapeutic effect, while an intrinsically lower systemic uptake of the intravesical route lowers the muscarinic receptor occupancy of exocrine glands to lower the adverse drug reaction relative to the oral route. Thus, the traditional pharmacokinetics and pharmacodynamics of oral treatment are upended by intravesical antimuscarinics to generate a dramatic improvement (~ 76%) noted in a meta-analysis of studies enrolling children with neurogenic lower urinary tract symptoms on the primary endpoint of maximum cystometric bladder capacity as well as the secondary endpoints of filling compliance and uninhibited detrusor contractions. The therapeutic success of intravesical multidose oxybutynin solution or oxybutynin entrapped in the polymer for sustained release in the pediatric population bodes well for patients with lower urinary tract symptoms at the other extreme of the age spectrum. Though generally used to predict oral drug absorption, Lipinski's rule of five can also explain the ten-fold lower systemic uptake from the bladder of positively charged trospium over oxybutynin, a tertiary amine. Chemodenervation by an intradetrusor injection of onabotulinumtoxinA is merited for patients with idiopathic overactive bladder discontinuing oral treatment because of a lack of efficacy. However, age-related peripheral neurodegeneration potentiates the adverse drug reaction risk of urinary retention that motivates the quest of liquid instillation, delivering larger fraction of onabotulinumtoxinA to the mucosa as opposed to muscle by an intradetrusor injection can also probe the neurogenic and myogenic predominance of idiopathic overactive bladder. Overall, the treatment paradigm of lower urinary tract symptoms in older adults should be tailored to individual's overall health status and the risk tolerance for adverse drug reactions.

Treatment of Overactive Bladder in the Elderly Female: The Case for Trospium, Oxybutynin, Fesoterodine and Darifenacin

Overactive bladder (OAB) is a common constellation of lower urinary tract storage symptoms that causes a significant impact on a person's quality of life. The elderly may be disproportionally impacted by these symptoms due to concomitant poor mobility, comorbid conditions such as diabetes and heart failure, and polypharmacy. While behavioral modification and pelvic floor muscle training should be considered first-line treatment options, pharmacotherapy remains the backbone of the therapeutic regimen. Trospium, oxybutynin, fesoterodine, and darifenacin all have unique properties that may confer certain advantages in the elderly population. The hydrophilicity and quaternary amine structure of trospium may limit its ability to cross the blood-brain barrier and thus minimize impact on cognition in the elderly. In its oral form, oxybutynin may have the most significant effect on cognition; however, the transdermal preparations may be favorable in the elderly population due to the ability to avoid first-pass metabolism and its limited antimuscarinic adverse effects. Fesoterodine may be the most extensively studied OAB medication in the elderly population. Darifenacin has a strong affinity for the M3 receptor in the bladder, while having a weak affinity for the M1 receptor commonly found in the brain. It must be noted that all muscarinic receptor antagonists are associated with common adverse effects to some degree, and frequent re-evaluation of the elderly patient is necessary to confirm the proper benefit-to-risk profile.

The short-term and long-term adverse ocular effects of fesoterodine fumarate

AIM

To evaluate the short-term and long-term effects of fesoterodine fumarate treatment which is used for overactive bladder (OAB) on pupil diameter (PD), intraocular pressure (IOP) and accommodation amplitude (AA).

METHOD

Ophthalmic examination was performed before and after receiving medication (on the 30th and 90th day) on 120 eyes of 120 women whom were planned to begin anticholinergic treatment (fesoterodine fumarate, 4 mg/day, peroral) for OAB, prospectively. The changes in PD, IOP and AA were analyzed statistically.

RESULTS

The mean age of 120 women was 52.06 ± 9.39 years (30-70 years). The mean PD, IOP and AA values were 4.12 ± 0.61 mm (3.00-5.70 mm), 15.58 ± 1.74 mmHg (11-20 mmHg) 2.28 ± 1.26 Diopter (D) (0.50-5.50 D) at baseline; 4.68 ± 0.65 mm (3.20-5.80 mm), 16.11 ± 1.72 mmHg (11-20 mmHg), 1.68 ± 1.04 D (0.25-4.50 D) at 30th day; and 4.28 ± 0.58 mm (3.10-5.70 mm), 16.09 ± 1.96 mmHg (11-19 mmHg), 2.18 ± 1.19 D (0.50-5.00 D) at 90th day, respectively. Although increases in PD values and decreases in AA values were statistically significant (p < 0.001 for each), the changes in IOP values were not as such (p = 0.642). Visual complaint was not observed in any patient.

DISCUSSION

The newest anticholinergic medication in women with OAB increased the PD and decreased the AA statistically significantly. Clinically, it seems to be well-tolerated by the patient.

Oxybutynin for the Treatment of Primary Hyperhidrosis: Current State of the Art

Oxybutynin is an anticholinergic drug with an emerging role in the treatment of hyperhidrosis. Several recent studies have documented that it is effective both in focal and generalized hyperhidrosis and shows universally good response among different groups of patients regardless of age, gender, and weight. The most common adverse event is dry mouth reported by almost all patients treated. The way this might affect long-term compliance and tolerability should be better investigated in the future.

The effect of oral solifenacin succinate treatment on intraocular pressure: glaucoma paradox during overactive bladder treatment

INTRODUCTION AND HYPOTHESIS

Anticholinergic medication is the mainstay of pharmacotherapy for overactive bladder (OAB). The aim of the study is to investigate the effect of oral solifenacin succinate on intraocular pressure (IOP) in female OAB patients and to discuss the ocular drawbacks during treatment.

METHODS

The female patients with a clinical diagnosis of OAB in whom use of oral solifenacin succinate 5 mg/day (group I) and age-matched healthy female subjects (group II) underwent complete ophthalmological examination, including IOP measurement at the beginning of the oral treatment and after 4 weeks. The patients with a history of previous ocular surgery and those with ocular diseases besides refraction disorders and presbyopia were excluded.

RESULTS

The data from the right eyes of 60 consecutive patients in group I and 30 consecutive patients in group II were used for analysis. No statistically significant change was detected in the IOP (from 16.05 ± 2.30 mmHg to 16.30 ± 2.25 mmHg at the 4th week in group I, p = 0.160; from 15.60 ± 2.14 mmHg to 15.60 ± 2.09 mmHg at the 4th week in group II, p = 0.864) of the eyes in both groups.

CONCLUSIONS

Since the power of the study is not enough to draw a clear conclusion, a 4-week course of solifenacin succinate treatment in women with OAB seemed to have no clinically significant effect on IOP values. Further larger studies are needed to determine the effect of anticholinergics on anterior chamber parameters and to evaluate their safety in glaucoma patients.

Oxybutynin: past, present, and future

Oxybutynin chloride is primarily indicated for the treatment of overactive bladder syndrome (OAB). It remains the most widely prescribed compound for OAB in the world. OAB is defined as the presence of urinary urgency, usually accompanied by daytime urinary frequency and nocturia, with or without urgency urinary incontinence, in the absence of infection or other identifiable etiology. This is a significant problem for men and women said to affect over 33 million adults in the USA, with the prevalence increasing with age. These symptoms can alter quality of life, with both physical and psychological impairment, as well as cause significant financial burden including the cost of sanitary supplies and decreased work productivity. Both pharmacological and non-pharmacological methods may be employed to aid in the treatment of OAB. The mainstay of treatment for OAB relies on pharmacological management, most specifically treatment with antimuscarinic medications. These medications are thought to prevent involuntary bladder contractions and/or urgency by inhibiting the muscarinic receptors within the urothelium and detrusor muscle. Currently, there are six different medications approved by the US Food and Drug Administration (FDA) for the treatment of OAB, with more than nine formulations including immediate- and extended-release tablets, transdermal patch and gel, vaginal ring, and suppository. This review will focus specifically on oxybutynin chloride, which has been used to treat OAB for four decades in numerous formulations.

[Urinary incontinence in woman: epidemiologic profile in Sub Saharian countries]

The objective of this study was to describe the epidemiologic profile of urinary incontinence of the African woman of three Sub Saharan African countries.

MATERIAL AND METHODS

A multicentric study summarized the epidemiological data collected in female from Nouakchott, Dakar and Ndjamena using a questionnaire. All participants filled an anonymous questionnaire including demographic data and marital status, medical, surgical, gynecological and obstetrical history and the characteristics of the urinary incontinence.

RESULTS

Overall, 3021 questionnaires were distributed, only 2070 answers (69%) could be processed. Mean age of the overall population was 28 years. Adult women aged less than 30 years accounted for 56% of the study population. The age group 30-49 years accounted for 42% of the population and only 2% of the study group had more than 50 years. The prevalence of incontinence was 367 cases over 2070 (17,7%). The types of incontinence found were: urgency in 28.6% of cases, stress incontinence in 38.4% of cases and mixed in 33% of cases. Approximately 23,9% of nulliparous and 23,5% of the multiparous had urinary incontinence. The leakage was occasional in 75% of the cases and regular in 25% of the cases. According to gravity, in 31% of cases the volume of urines lost necessitated a change of underwear. Of the women presenting urinary incontinence, 85 (23%) consulted a doctor. A psychosocial repercussion was found in 31% of the cases.

CONCLUSION

Urinary incontinence is much more frequent in our areas than it was thought to be because it was rarely acknowledged.

Randomized Trial of Oxybutynin Extended Versus Immediate Release for Women Aged 65 and Older with Overactive Bladder: Lessons Learned from Conducting a Trial

OBJECTIVE

This trial was designed to investigate the effectiveness of extended release versus immediate release oxybutynin in reducing symptoms of overactive bladder in a community-dwelling female population over the age of 65.

METHODS

This was a prospective randomized 12-week, open-label study. The primary outcome was number of micturitions per 24 hours, 12 weeks after treatment. The a priori sample size estimate was 60 patients per group.

RESULTS

Of the 318 women approached, only 72 women (23%) were enrolled over 34 months (33 in the immediate release group, and 39 in the extended release group). The study was stopped prematurely because of recruitment difficulties and an interim analysis revealing the need for a much larger sample than had been estimated to show a significant difference between treatments. After 12 weeks of treatment, there was no difference between the oxybutynin extended release and immediate release groups in the number of micturitions per 24 hours or in other outcomes.

CONCLUSION

This study did not demonstrate differences between oxybutynin extended release and immediate release and in reducing symptoms of overactive bladder or quality of life, possibly because the study did not reach the necessary sample size. The difficulty in recruiting subjects for the trial likely resulted from the onerous study requirements (4 study visits required over 12 weeks) and the downtown location of the study centres: these factors would cause particular difficulties for women over age 65 with overactive bladder, for whom travelling may be a problem. Evidence is needed to guide prescribing for older patients, but designing research to obtain adequate sample sizes is difficult. Studies in older subjects should ensure that a much larger budget is allocated for recruitment than would be allocated for studies in younger subjects, that meticulous attention is paid to issues of transport and access, and that support is provided for subjects who agree to take part research.

Tolterodine: a new antimuscarinic agent for the treatment of the overactive bladder

Bladder hyperactivity is a debilitating problem that affects many individuals. A plethora of therapeutic options have been investigated to combat this condition, antimuscarinic therapy being the most widely used. Nevertheless, this medication group has historically been of limited benefit, due to its side-effect profile. Tolterodine is a new muscarinic receptor antagonist that has been shown to be equally effective when compared to oxybutynin. However, the side-effect profile for tolterodine is much better than this commonly used anticholinergic. It has reduced affinity for the salivary glands in animal studies, and, in clinical trials, there has been a reduced incidence of dry mouth with this medication. In Phase III studies, tolterodine has been shown to decrease the number of micturitions per day, decrease the number of incontinence episodes per day and increase the mean volume voided per micturition. The maximal effect of this medication may not be seen for 6 - 8 weeks after initiation of the drug although the exact explanation for this finding has yet to be completely elucidated. The recommended dose is 2 mg b.i.d., which should be adjusted for those with liver failure or those on drugs that inhibit the cytochrome P450 isoenzyme known as CYP3A4. In summary, tolterodine is an effective well-tolerated antimuscarinic which should be considered as a first-line treatment due to its more favourable side-effect profile when than other available medications.

Managing patients with an overactive bladder and glaucoma: a questionnaire survey of Japanese urologists on the use of anticholinergics

OBJECTIVES

To establish the views of urologists on the use of anticholinergic drugs for treating the overactive bladder (OAB) in patients with glaucoma.

SUBJECTS AND METHODS

In February 2004 a self-description questionnaire was mailed to all 417 urologists who were members of the Tokai Society of Voiding Dysfunction, to determine current practice in Japan for patients with an OAB and glaucoma. Subgroups were analysed between the types of practice and the duration since the urologists had graduated from medical school.

RESULTS

Of the 155 respondents, 76 (49%) routinely enquired about a history of glaucoma before prescribing anticholinergics, and 45 (29%) routinely referred patients with such a history to ophthalmologists. To treat patients with OAB and glaucoma, 102 (66%) would prescribe anticholinergics if permission were available from the ophthalmologist, 33 (21%) chose other treatments and 17 (11%) abandoned treatment. Forty-nine urologists (32%) were currently prescribing anticholinergics to patients with glaucoma. As to knowledge about glaucoma, 132 (85%) urologists knew that there were two types of glaucoma and 98 (63%) knew about laser iridotomy. The proportion of urologists who knew of the two types of glaucoma and asked patients for this information was significantly higher in university than in general hospitals (P < 0.05).

CONCLUSIONS

Although anticholinergic drugs can precipitate angle-closure glaucoma by pupillary block, they are not contraindicated in open-angle glaucoma or in angle-closure glaucoma that has already been treated by laser iridotomy. Not all urologists are aware of this difference, at least in Japan. Some urologists avoid anticholinergics in all patients with glaucoma, while others pay little attention to glaucoma. Routine history taking and referral to ophthalmologists allows many patients with OAB and glaucoma to benefit safely from anticholinergics. Moreover, clinicians should be aware of patients with OAB who have not been evaluated by ophthalmologists but who are at risk of angle-closure glaucoma.

Neurological disorders cerebrovascular disease and parkinsonism

To store and expel urine at appropriate intervals, the lower urinary tract requires extensive input and control from the peripheral autonomic, somatic, and central nervous systems. Neurological disorders, such as cerebrovascular disease and Parkinson's disease, often cause functional disturbances of the lower urinary tract.

A benefit-risk assessment of extended-release oxybutynin

Oxybutynin is a muscarinic receptor antagonist, which has been available for a number of years in its original immediate-release (IR) formulation. While oxybutynin IR has proven effective for the treatment of overactive bladder, its extended use can be limited by adverse effects, particularly dry mouth. An extended-release (ER) formulation of oxybutynin based on the OROS system has recently become available, which allows once daily administration. In direct comparison to oxybutynin IR, oxybutynin ER has an increased oral bioavailability for the parent compound oxybutynin which is accompanied by a reduced bioavailability for the active metabolite N-desethyl-oxybutynin. The latter has been implicated in mediating a major part of the adverse effects of oxybutynin treatment. Two double-blind, placebo-controlled, randomised studies in patients with overactive bladder have demonstrated that oxybutynin ER has a similar efficacy as oxybutynin IR but with improved tolerability. This is in line with clinical pharmacological studies demonstrating a smaller impairment of saliva production with oxybutynin ER than with oxybutynin IR. Thus, the ER formulation of oxybutynin maintains the therapeutic benefits and concomitantly improves tolerability.

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.

Twelve-month treatment of overactive bladder: efficacy and tolerability of tolterodine

CONTEXT

Tolterodine is a bladder-selective antimuscarinic agent designed for the treatment of overactive bladder. Traditional antimuscarinic therapies are poorly tolerated due to a high incidence of anticholinergic adverse events and consequently few patients remain on long term therapy.

OBJECTIVE

To evaluate the long term efficacy and tolerability of tolterodine in patients with symptoms of overactive bladder.

DESIGN

Twelve-month open-label extension of 4 randomised, placebo-controlled, double-blind, multinational, multicentre trials of 4 weeks' duration.

PATIENTS

714 patients (aged 18 to 92 years) with symptoms of overactive bladder who completed the double-blind portion of the studies.

INTERVENTION

Tolterodine 2 mg twice daily for up to 12 months.

MAIN OUTCOME MEASURES

Micturition diary variables: number of micturitions per 24 hours, number of urge incontinence episodes per 24 hours, mean urine volume voided per micturition. Safety variables: adverse events, study discontinuation rate.

RESULTS

A total of 441 patients (62%) completed 12 months' open-label treatment with tolterodine, which significantly reduced the number of micturitions per 24 hours [mean change -2.4, 95% confidence interval (CI) -2.7 to -2.2, median change -20%, p < 0.0001] and number of urge incontinence episodes per 24 hours (mean change -1.3, 95% CI -1.6 to -1.0, median change -74%, p < 0.0001), while the mean volume voided per micturition was significantly increased (+33 ml, 95% CI +28 to +38, median change +18%; p < 0.0001). 41% of patients reported dry mouth (27% mild, 10% moderate, 3% severe). Dosage reduction to 1 mg twice daily was required in 23% of patients. 15% of patients withdrew from the study due to adverse events, with 5% having associated dry mouth.

CONCLUSIONS

The high percentage of patients completing 12 months' treatment indicates that tolterodine is an effective and well tolerated agent for long term treatment of overactive bladder.

Tolterodine: a review of its use in the treatment of overactive bladder

Tolterodine is a competitive muscarinic receptor antagonist that shows in vivo selectivity for the bladder over the salivary glands compared with oxybutinin. Results of randomised double-blind placebo-controlled studies indicate that tolterodine 4 mg/day (administered as immediate-release tablets 2mg twice daily or extended-release capsules 4mg daily) is superior to placebo in improving micturition diary variables in patients with overactive bladder. Moreover, tolterodine 2mg twice daily is as effective as oxybutynin 5mg 3 times daily. Maximum treatment effects with both drugs occurred after 5 to 8 weeks of treatment and improvements were maintained during long term treatment for up to 24 months. In a pooled analysis of four 12-week studies, equivalent and significant reductions in micturition frequency (-2.3 and -2.0 vs -1.4, p < 0.001) and the incidence of urge incontinence episodes (-1.6 and -1.8 vs -1.1, p < 0.05) were reported for tolterodine 2mg twice daily and oxybutynin 5mg 3 times daily compared with placebo. Functional bladder capacity was also significantly increased. Improvements in patient perceptions of their urgency symptoms and of problems caused by their bladder condition were significantly greater during treatment with tolterodine than with placebo. Tolterodine was generally well tolerated in clinical trials of up to 24 months' duration. Dry mouth was the most frequent adverse event. The incidence (40 vs 78%, p < 0.001) and intensity of this event was lower with tolterodine 2mg twice daily than oxybutynin 5mg 3 times daily. Additionally, a 23% lower incidence of dry mouth was reported with once daily extended-release tolterodine capsules than with twice daily immediate-release tablets (p < 0.02). The incidence of adverse CNS events with tolterodine was low and similar to that of placebo. Tolterodine was well tolerated in elderly patients and no serious tolerability concerns were identified.

CONCLUSION

Tolterodine is the first antimuscarinic agent to specifically developed for the treatment of overactive bladder. The functional selectivity of tolterodine for the bladder translates into good efficacy and tolerability in patients, including the elderly, with overactive bladder. Tolterodine is as effective as oxybutynin in improving micturition diary variables but is associated with a significantly lower incidence and intensity of dry mouth. This favourable tolerability profile, together with sustained clinical efficacy during long term treatment, places tolterodine as valuable treatment for the symptoms of overactive bladder.

Tolterodine: a safe and effective treatment for older patients with overactive bladder

OBJECTIVE

To investigate the clinical safety and efficacy of two dosages of tolterodine in older patients with symptoms attributable to overactive bladder.

DESIGN

Randomized, double-blind, placebo-controlled, parallel-group, multinational, phase III study.

SETTING

Incontinence, older care, urological, and urogynecological clinics in the United Kingdom, France, and the Republic of Ireland.

PARTICIPANTS

One hundred and seventy-seven older patients (age > or =65 years) with symptoms of urinary urgency, increased frequency of micturition (> or =8 micturitions/24 hours), and/or urge incontinence (> or =1 episode/24 hours).

INTERVENTION

Tolterodine 1 mg or 2 mg twice daily (bid), or placebo, for 4 weeks.

MEASUREMENTS

Safety and tolerability were evaluated through spontaneously reported adverse events, electrocardiogram, and blood pressure measurements. Efficacy was assessed using micturition diary variables: mean change from baseline in frequency of micturition and number of incontinence episodes/24 hours.

RESULTS

The mean age of the patient population was 75 years. Overall, > or =87% of patients completed the study. Neither dosage of tolterodine was associated with serious drug-related adverse events during the study. No cardiac arrythmogenic events were noted. Dry mouth (mild to moderate intensity) was the most common adverse event in both the placebo and tolterodine treatment groups. Three percent of patients in the tolterodine 2 mg bid group discontinued treatment because of dry mouth, compared with 2% of placebo-treated patients. Compared with placebo, statistically significant decreases in micturition frequency were apparent in both tolterodine treatment groups. Furthermore, patients treated with tolterodine 2 mg bid had statistically significant decreases in urge incontinence episodes/24 hours and increases in volume voided per micturition compared with placebo.

CONCLUSION

Tolterodine (taken for 4 weeks) is safe and shows efficacy, particularly at a dosage of 2 mg bid, in the treatment of older patients with urinary symptoms attributable to overactive bladder.

The overactive bladder in children: a potential future indication for tolterodine

OBJECTIVE

To determine the safety, efficacy and pharmacokinetics of tolterodine in children with an overactive bladder.

PATIENTS AND METHODS

Thirty-three children (20 boys and 13 girls, aged 5-10 years) with an overactive bladder and symptoms of urgency, frequency and/or urge incontinence were enrolled in an open, dose-escalation study. Patients were treated with oral tolterodine 0.5 mg (n = 11), 1 mg (n = 10) or 2 mg (n = 12) twice daily for 14 days. The primary safety endpoint was the change in residual urinary volume, as determined by ultrasonography. In addition, voiding diary variables (frequency and incontinence episodes) and pharmacokinetics were evaluated. Other safety endpoints included laboratory variables, electrocardiogram recordings and reported adverse events.

RESULTS

There were no safety concerns in terms of the change in residual urinary volume for any of the three dosage groups; values were comparable with baseline after 2 weeks of treatment for all three dosages. Adverse events were reported by 20 patients (six on 0.5 mg, five on 1 mg, and nine on 2 mg). Most adverse events were not considered to be drug-related; of the 13 possibly related events, 10 occurred in those taking 2 mg. Headache was the most commonly reported adverse event. No serious adverse events were reported and there were no general safety concerns. There was an improvement in voiding diary variables in all treatment groups after 2 weeks of treatment, although the efficacy was greatest in those taking 1 mg and 2 mg. Pharmacokinetic findings were consistent with dose linearity over the range 0.5-2 mg.

CONCLUSION

The results support the use of 1 mg twice daily as the optimal dose of tolterodine for treating children aged 5-10 years with an overactive bladder.

A randomized controlled trial comparing the efficacy of controlled-release oxybutynin tablets (10 mg once daily) with conventional oxybutynin tablets (5 mg twice daily) in patients whose symptoms were stabilized on 5 mg twice daily of oxybutynin

OBJECTIVE

To compare the efficacy of a controlled-release (CR) formulation of oxybutynin with that of conventional oxybutynin in patients with detrusor instability or detrusor hyper-reflexia whose symptoms were stabilized on conventional oral oxybutynin tablets.

PATIENTS AND METHODS

The study comprised a randomized, double-blind, parallel-group trial involving 130 patients drawn from 15 centres in the UK. The study was of 6 weeks' duration, i.e. 2 weeks of screening whilst taking conventional oxybutynin tablets (5 mg twice daily) followed by 4 weeks of double-blind treatment with either CR oxybutynin tablets (10 mg once daily) or conventional oxybutynin tablets (5 mg twice daily). Outcome measures were changes in 24-h frequency and 24-h incontinence episodes recorded throughout the study on diary charts. Adverse events were recorded by patients in their diary charts and serum concentrations of oxybutynin and its active metabolite, N-desethyloxybutynin, were measured at baseline and at completion of the study to detect possible drug accumulation.

RESULTS

The treatments did not differ significantly in any of the outcome measures. The primary efficacy criterion was the daytime continence at completion of the study; 53% and 58% of patients were continent on CR and conventional oxybutynin treatments, respectively (the 95% confidence interval of the difference in the proportion being - 22% to 13%; P = 0.62). The total number of side-effects experienced by those patients receiving treatment with the CR formulation was 57% of that for patients receiving treatment with conventional oxybutynin. Individual side-effects showed a similar distribution within treatment groups. There was no evidence of the accumulation of oxybutynin or N-desethyloxybutynin during the multiple dosing of CR or conventional oxybutynin tablets.

CONCLUSION

The CR and conventional formulations of oxybutynin did not differ in their efficacy, and the CR formulation was associated with fewer side-effects. In addition, CR oxybutynin appeared to maintain therapeutic blood levels over the 24 h dosing interval with no accumulation of oxybutynin or its active metabolite. Once-daily dosing with a CR tablet is seen as convenient for the patient and is expected to result in improved compliance in patients already stabilized on conventional oxybutynin treatment.

Analysis of the electrophysiologic effects of short-term oxybutynin on guinea pig and rabbit ventricular cells

The objective of this study was to investigate the cardioactive properties of oxybutynin, a drug that is widely prescribed for management of voiding dysfunction. Membrane currents were recorded from whole-cell-configured guinea pig ventricular myocytes, and action potentials were recorded from guinea pig and rabbit papillary muscles. L-type Ca2+ current (I(Ca),L), inward-rectifier K+ current (I(K1)), and delayed-rectifier K+ current (I(K)) were unaffected by < or = 1 microM oxybutynin, and inhibited by higher concentrations. The concentrations that reduced the currents to one-half of predrug control amplitude (K0.5) were as follows: 1(Ca),L, 16.1 microM, I(K1), 18.2 microM, rapidly activating I(K)(I(Kr)), 11.4 microM, and slowly activating I(K)(I(Ks)), 28.7 microM. Action-potential durations at 20 and 90% repolarization (APD20, APD90) were unaffected by oxybutynin < or =3 microM in guinea pig papillary muscles driven at 1 Hz; higher concentrations selectively shortened the APD20 by as much as 25% (100 microM), and caused moderate reductions in maximal upstroke velocity. Changes in the action potentials of rabbit papillary muscles were even smaller than in the guinea pig muscles. Because the peak therapeutic plasma concentration of oxybutynin is in the 0.01-0.1 microM range, the results suggest that the drug is highly unlikely to have adverse effects on cardiac electrical activity.

Tolterodine, a new antimuscarinic agent: as effective but better tolerated than oxybutynin in patients with an overactive bladder

OBJECTIVE

To compare the efficacy and tolerability of tolterodine with that of oxybutynin in patients with an overactive bladder.

PATIENTS AND METHODS

A randomized, double-blind, placebo-controlled, parallel group, multinational phase-III study was conducted in urology and gynaecology clinics in the UK, Republic of Ireland and Sweden. The study enrolled 293 patients with urodynamically confirmed bladder overactivity, increased frequency of micturition (> or = micturitions/24 h) and symptoms of urgency and/or urge incontinence (> or = 1 episode/24 h). Patients received either tolterodine (2 mg twice daily) or oxybutynin (5 mg three times daily) or placebo. Doses could be reduced, to prevent withdrawal, to 1 mg or 2.5 mg, respectively. The main outcome measures were the mean change from baseline in frequency of micturition/24 h, the number of incontinent episodes/24 h and volume voided per micturition.

RESULTS

After 12 weeks' treatment, the mean frequency of micturition decreased by 21% and 19.5% in those receiving tolterodine (n = 118) and oxybutynin (n = 118), respectively, and by 10.5% in those on placebo (n = 57). Among those with urge incontinence at baseline (75% of patients), the mean number of incontinent episodes decreased by 47%, 71% and 19%, respectively, in those receiving tolterodine, oxybutynin and placebo. The effect of tolterodine and oxybutynin on these two micturition variables was statistically equivalent. There was also a comparable increase in mean volume voided per micturition in the tolterodine (27%) and oxybutynin groups (31%), compared with 7% in the placebo group. Dry mouth was the most common adverse event and was reported with greater frequency and intensity among patients receiving oxybutynin than among those receiving either tolterodine or placebo. In the oxybutynin group, more patients also withdrew because of adverse events and a greater proportion required dose reduction as a result of adverse events. Despite dose reduction, the frequency of adverse events and the intensity of dry mouth remained higher among those receiving oxybutynin (2.5 mg three times daily) than in patients who remained on tolterodine 2 mg twice daily.

CONCLUSION

Tolterodine 2 mg twice daily is effective and well tolerated in the treatment of bladder overactivity. Tolterodine was better tolerated than oxybutynin, particularly with respect to the frequency and intensity of dry mouth, but had comparable clinical efficacy. The superior tolerability of tolterodine therefore allows more patients to remain on effective therapy than the current most commonly prescribed agent for the treatment of the overactive bladder.

Cytochrome P450 specificity of metabolism and interactions of oxybutynin in human liver microsomes

Oxybutynin has an extensive first pass metabolism after oral administration, the main active metabolite being N-desethyloxybutynin. The purpose of this study was to investigate the CYP isoform specificity of oxybutynin N-deethylation and possible interactions. Oxybutynin N-deethylation in human liver microsomes in vitro was potently inhibited by ketoconazole (IC50 4.5 microM), less and variably by itraconazole and not by quinidine or several other reference inhibitors, suggesting that CYP3A enzymes are predominant catalysts of the reaction. Recombinant CYP3A5 enzyme had higher activity in oxybutynin N-deethylation than recombinant CYP3A4. Ketoconazole inhibited oxybutynin N-deethylation by the recombinant CYP3A4 and CYP3A5 almost completely, whereas itraconazole inhibited the activity of CYP3A4 more potently than that of CYP3A5. Oxybutynin inhibited CYP3A4- and CYP2D6- associated activities (testosterone 6 beta-hydroxylase and dextromethorphan O- demethylase, respectively) in human liver microsomes. CYP1A1/2-, CYP2A6-, CYP2C9- and CYP2E1-associated activities were inhibited less potently or not at all by oxybutynin when compared with reference inhibitors. Although the reasons for the weak and variable inhibition by itraconazole remain to be studied, it seems that oxybutynin is predominantly metabolized by CYP3A4 and CYP3A5 but not by CYP2D6. However, it seems to have some affinity also to the latter enzyme.

Identification of medications that cause cognitive impairment in older people: the case of oxybutynin chloride

OBJECTIVES

To evaluate the cognitive effects of acute challenges with the antispasmodic agent oxybutynin hydrochloride in normal older volunteers and to compare these effects with those attributable to diphenhydramine, another commonly used medication with anticholinergic (muscarinic-blocking) activity.

DESIGN

A double-blind, placebo-controlled cross-over study.

SETTING

Laboratory evaluations of community subjects.

PARTICIPANTS

A convenience sample of 12 volunteers, average age 69.17 years.

INTERVENTION

Baseline assessment was followed by randomized administration of a placebo, oxybutynin hydrochloride (5 and 10 mg), and diphenhydramine hydrochloride (50 mg) in test sessions separated by 1 week.

MEASUREMENTS

Evaluation of cognitive performance with a 1-hour battery of pencil and paper, interviewer-administered, and computer-administered tests beginning 90 minutes after drug (or placebo) administration.

RESULTS

Random regression analyses demonstrated that oxybutynin caused significant cognitive decrements on seven of 15 cognitive measures, and diphenhydramine caused decrements on five measures. The most sensitive measures for detecting the effects of oxybutynin hydrochloride were the Buschke Selective Reminding Test and Reaction Time.

CONCLUSIONS

These findings demonstrate that oxybutynin can cause cognitive impairment and suggest that physicians prescribing it should monitor their patients to facilitate the early recognition of those who experience drug-related cognitive deficits. More generally, the findings demonstrate that systematic research with normal volunteers can identify cognitive toxicity not recognized during the process of drug development or postmarketing surveillance.

Clinical efficacy and safety of tolterodine in the treatment of overactive bladder: a pooled analysis

OBJECTIVES

To examine the safety, efficacy, and tolerability of tolterodine in four randomized, double-blind, parallel, multicenter, 12-week studies of patients with overactive bladder.

METHODS

Two of the four studies compared tolterodine (2 mg twice daily) to oxybutynin (5 mg three times daily) and placebo, one study compared tolterodine (2 mg twice daily) to oxybutynin (5 mg three times daily), and one study compared two dosages of tolterodine (1 and 2 mg twice daily) to placebo. Efficacy was determined from micturition diaries and patient perception of their bladder condition. Safety and tolerability were assessed from adverse events and laboratory measures.

RESULTS

A total of 1,120 patients were randomized and treated at 134 centers. For the primary efficacy variable, the number of micturitions/24 hours, pooled results showed a significant decrease from baseline for the 1 mg tolterodine (P < 0.001), 2 mg tolterodine (P < 0.001), and 5 mg oxybutynin (P < 0.01) groups, compared to placebo. Both tolterodine doses and oxybutynin significantly decreased incontinence episodes/24 hours and significantly increased volume voided/micturition, compared to placebo. Tolterodine at a dose of 2 mg twice daily and 5 mg oxybutynin twice daily were significantly more effective in improving patient perception of bladder condition than placebo. Tolterodine at a dose of 2 mg and 5 mg oxybutynin were equivalent in their effectiveness. Tolterodine at doses of 1 mg and 2 mg were tolerated significantly better than oxybutynin when adverse events, dry mouth (both frequency and intensity), dose reductions, and patient withdrawals were considered.

CONCLUSIONS

Although oxybutynin is highly effective, its clinical utility is limited by systemic side effects that lead to frequent discontinuation of treatment or dose reductions. Patients receiving tolterodine should not experience these limitations and instead will get safe and long-term effective treatment for their condition.

Efficacy and safety of two doses of tolterodine versus placebo in patients with detrusor overactivity and symptoms of frequency, urge incontinence, and urgency: urodynamic evaluation. The International Study Group

Tolterodine is a new competitive muscarinic receptor antagonist developed for the treatment of the unstable bladder. A total of 242 patients were enrolled in a multicenter, multinational, randomized, double-blind, placebo-controlled study conducted over a period of 4 weeks in patients with detrusor overactivity and symptoms of frequency, urgency, and urge incontinence. The objective of the study was to compare the efficacy and safety of tolterodine given at 1 or 2 mg b.i.d. versus placebo. At week 4 a statistically significant increase in the volume at first contraction (p = 0.030) and maximal cystometric capacity (p = 0.034) was only in the tolterodine 2 mg b.i.d. group. Tolterodine was safe and generally well tolerated. The incidence of dry mouth, as the most commonly reported adverse event, was only 9% and of mild to moderate intensity.

Does oxybutynin add to the effectiveness of prompted voiding for urinary incontinence among nursing home residents? A placebo-controlled trial

OBJECTIVE

To determine if oxybutynin, a bladder relaxant medication, adds to the effectiveness of prompted voiding (PV) in the management of urinary incontinence among nursing home residents.

DESIGN

Randomized, placebo-controlled, double-blinded, dose-adjusted, crossover trial of oxybutynin added along with PV.

SETTING

Seven nursing homes in Los Angeles County, California.

PARTICIPANTS

Seventy-five nursing home residents with predominantly urge incontinence, whose incontinence did not respond well to a trial of PV.

MAIN OUTCOME MEASURES

The frequency of incontinence, measured as the percentage of hourly (7 AM to 7 PM) physical checks over a 3-day period at which the resident was found wet.

RESULTS

Sixty-three (84%) of the residents completed the study. Among those completing the trial, the percent of checks wet went from 26.5% to 23.7% on placebo to 20.2% on active drug. These changes were statistically significant but not clinically meaningful. A clinically significant decrease in the frequency of incontinence, which we defined as a relative reduction in the percent of checks wet of > 33%, occurred in 20 subjects (32%) while on active drug and in 12 subjects (19%) while on placebo (P = .48 by chi-square). Twenty-five subjects (40%) met our "continence criteria" of an average of one or less wet per day while on active drug, and 11 subjects (18%) achieved this goal on placebo (P = .005 by chi-square).

CONCLUSION

Oxybutynin does not add to the clinical effectiveness of PV in the majority of nursing home residents with urge type urinary incontinence. Selected residents may, however, become more responsive to PV while on oxybutynin. Our data are consistent with other studies of bladder relaxant medications in functionally impaired populations. New drugs and/or other interventions are needed for the large number of incontinent nursing home residents who do not respond well to PV.

Measurement of oxybutynin and its N-desethyl metabolite in plasma, and its application to pharmacokinetic studies in young, elderly and frail elderly volunteers

1. A quantitative h.p.l.c. plasma assay for oxybutynin (OB) and its active metabolite, N-desethyl oxybutynin (DEOB) is described. The method is linear with coefficients of variation ranging between 4 and 11.8% for OB and 4.6-9.1% for DEOB over the typical concentration range measured. Minimum detectable levels were 0.5 and 5 ng/ml for OB and DEOB respectively from a 2 ml sample. 2. Pharmacokinetic parameters were obtained after a single oral dose of OB and after administration two or three times daily to frail elderly and elderly volunteer groups respectively. Single dose results were also compared with data from young healthy volunteers. 3. There was a wide range in peak blood levels and high levels of parent drug were matched by high DEOB metabolite levels. Plasma levels on repeated administration were as would be predicted from the single dose kinetics. 4. Area under the plasma time course curve for DEOB metabolite was less than or equal to 5 than that of the parent drug. 5. A trend of increasing peak plasma levels and bioavailability was observed with increasing age and frailty, with the differences more apparent between the active elderly and frail elderly groups than between the active elderly and young volunteers. 6. Results indicate that for frail elderly patients a lower initial starting dose of 2.5 mg OB given two or three times a day may provide adequate therapeutic blood levels of the drug.

Behavioral and pharmacological treatment of persistent urinary incontinence in the elderly

Research has demonstrated that behavioral interventions can help to decrease or eliminate urinary incontinence. Pharmacological agents have also been shown to be effective in the management of this problem. This article describes simple low risk behavioral techniques and pharmacological approaches that can be used by nurse practitioners to assist their incontinent patients to control this embarrassing and expensive problem.

Urinary incontinence: medical and psychosocial aspects

Recognition has been growing over the past two decades that urinary incontinence is a rather widespread condition among older adults. Prevalence rates of about 30% for any incontinence and about 5% for severe incontinence among older adults were suggested by several European studies and have recently been confirmed by American studies. The rates are typically higher among women than men. Despite these findings, much about the true distribution of urinary incontinence remains to be firmly established. The proportion of different types and the differences between sexes, ages, and races need to be confirmed using representative population samples and valid measures of incontinence. These distributions cannot be accurately described using clinical populations. Perhaps because urinary incontinence is viewed as highly embarrassing, it has not been a focus of media coverage or public discussion. More attention by the media and by health-care professionals would build public awareness of the condition. Older adults and their caregivers need to know that urinary incontinence is common and treatable, so that they will identify it promptly and bring it to their physicians' attention. Health-care providers and social workers must also be alert to the possibility of incontinence among their clients. They should be prepared to ask older patients directly, because many patients may disregard urine loss or be too embarrassed to mention it. Currently, much of the management of urinary incontinence appears to be self-devised. Many incontinent persons have not talked to a physician about their problem. The largest proportion of those who attempt to control their urine loss use absorbent products or try to avoid loss by awareness of toilet locations and frequent toileting. Reliance on these methods is unfortunate because much progress has been made in developing diagnostic and treatment procedures for urinary incontinence. For example, surgical procedures to rectify an incompetent sphincter have been shown to be effective and are generally accepted. There are a number of medications effective for controlling detrusor instability. Further, various behavioral techniques appear to be promising as noninvasive initial interventions for many patients. We are on weaker ground regarding the prevention of and early intervention in urinary incontinence. The existing epidemiological data on the development of incontinence are poor. We do not know the proportion of urinary incontinence that is transient and the proportion that is chronic or established. Nor do we know the risk factors for onset and progression of the condition.(ABSTRACT TRUNCATED AT 400 WORDS)