Drug therapy for urinary incontinence

The effect of long-term hormonal treatment on voiding patterns during filling cystometry and on urethral histology in a postpartum, ovariectomized female rat

OBJECTIVE

To study whether long-term treatment with oestrogen (E(2) ), selective E(2) receptor modulators (SERMs), or growth hormone (GH) can prevent the development of abnormal voiding patterns during filling cystometry (CMG) in a postpartum, ovariectomized (Ovx) female rat.

MATERIALS AND METHODS

Immediately after spontaneous delivery, 60 primiparous Sprague-Dawley rats were randomly divided into six equal groups. One group served as uninjured sham controls and five groups underwent intravaginal balloon dilatation. On day seven, previously dilated rats underwent bilateral Ovx and implantation of a subcutaneous hormone-delivery pump. The five treatment groups received normal saline (control), E(2) , raloxifene, levormeloxifene, or GH for 7 weeks. Conscious CMG was performed 7 weeks after Ovx. Urethral sphincter tissue was harvested for elastin immunohistochemistry and real-time polymerase chain reaction of α(1A) -adrenoceptor mRNA.

RESULTS

No abnormal voiding patterns were detected in the group treated with GH. The E(2) , raloxifene and levormeloxifene groups had greater detrusor overactivity and urethral relaxation incontinence than control rats. The raloxifene group had a significantly lower baseline bladder pressure and opening pressure. GH-treated rats had higher elastin content in the urethra. Urethral α(1A) -adrenoceptor mRNA concentration was significantly lower in the SERM-treated rats compared with controls.

CONCLUSIONS

GH prevents the development of abnormal voiding patterns during filling CMG in a rat model of parturition-induced incontinence; E(2) and SERMs may worsen voiding patterns.

New insights into molecular targets for urinary incontinence

Urinary incontinence (UI) is a disease affecting quality of life of 200 million patients worldwide. It is characterized by involuntary loss of urine. The factors involved are cystitis, detrusor hyperreflexia, spinal injury, benign prostatic hyperplasia, etc. The surge in the number of reviews on this subject indicates the amount of research devoted to this field. The prevalence is increasing at an alarming rate but unfortunately, only a few medications are currently available for this condition. There are peripheral as well as central targets including cholinergic, vanilloid, prostaglandin, kinin, calcium channel, cannabinoid, serotonin, and GABA-receptors, which act by different mechanisms to treat different types of incontinence. Drugs acting on the central nervous system (CNS) increase urinary bladder capacity, volume, or pressure threshold for micturition reflex activation while peripherally acting drugs decrease the amplitude of micturition contraction and residual volume. Anticholinergic drugs specifically M3 receptor antagonists are the first choice but have frequent side effects such as dry mouth, CNS disturbances, etc. Therefore, there is a need to understand the biochemical pathways that control urinary dysfunction to determine the potential to which they can be exploited in the treatment of this condition. This article reviews the central and peripheral molecular targets and the potential therapeutic approaches to the treatment of UI.

In vitro effects of the cyclooxygenase inhibitor indomethacin and of the phospholipase-C inhibitor U-73122 on carbachol-induced contractions of porcine detrusor muscle

Prostaglandin synthetase inhibitors belong to one substance class additionally used in the treatment of bladder dysfunctions associated with involuntary bladder contractions. However, the mechanism of action of non-steroidal anti-inflammatory drugs (NSAIDs) on the detrusor muscle is not clear. In this study, it was examined in vitro whether the NSAID indomethacin exhibited an inhibitory effect on carbachol-induced contractions of the porcine detrusor muscle. Additionally, the inhibitory effect of the phospholipase-C inhibitor U-73122 on carbachol-induced contractions of the porcine detrusor muscle was investigated. Experiments were performed on the muscle strips of the porcine detrusor muscle suspended in a tissue bath. Effects of indomethacin at 10(-6) and 10(-5) M on the maximum carbachol-induced contraction and on the carbachol-response curve were investigated. Additionally, the inhibitory influence of U-73122 at a concentration of 10(-5.5) M on the carbachol-response curve was investigated. Pretreatment with indomethacin at both concentrations did not result in a significant reduction in the maximum contraction compared with the control. In the experiments in which carbachol concentration-response curves were generated, indomethacin exhibited at both concentrations a very small but significant change at carbachol concentrations of 10(-8) and 10(-7.5) M. In the experiments with U-73122, a significant change was found in the concentration-response curve of carbachol at all concentrations of carbachol from 10(-6.5) to 10(-4) M. The mean maximum carbachol-induced contraction was 141.8 +/- 6.8% after incubation with U-73122 and 166.0 +/- 6.4% in the control group (P < 0.05). Indomethacin did not inhibit the carbachol-induced contractions of the porcine detrusor muscle. The cyclooxygenase does not play a significant role in the carbachol-induced bladder contraction of the porcine detrusor muscle. The inhibitory action of the phospholipase-C inhibitor U-73122 on the carbachol-induced contraction was significant, but small. The results point to an inferior role of this pathway.

The potential of hormones and selective oestrogen receptor modulators in preventing voiding dysfunction in rats

OBJECTIVE

To investigate whether oestrogen, selective oestrogen receptor modulators (SERMs), and growth hormone (GH) can prevent the development of voiding dysfunction in a postpartum postmenopausal rat model of voiding dysfunction.

MATERIALS AND METHODS

Immediately after spontaneous delivery, nine primiparous Sprague-Dawley rats served as uninjured controls (sham group) and 54 underwent intravaginal balloon dilation. On day 7, the 54 subject rats underwent bilateral ovariectomy. A week later, six treatment groups of nine rats were randomized to receive: normal saline (injured control group), 17beta-oestradiol (E(2)), raloxifene, levormeloxifene, GH, or GH + E(2). The treatment groups received daily subcutaneous injections for 3 weeks. The effects of hormone treatment were examined by conscious cystometry at the end of the study. Voiding dysfunction was defined to include overactive bladder and sphincter deficiency.

RESULTS

The sham rats had a mean (sd) voiding frequency of 3 (0.87) times in 10 min and a bladder capacity of 0.43 (0.13) mL with smooth cystometry curves. The number of rats in each treatment group (each group contained nine rats) that had voiding dysfunction was as follows: E(2), three; raloxifene, six; levormeloxifene, four; and controls, four (P > 0.05 among the groups). Only one rat in the GH-treated group and no rats in the GH + E(2)-treated group had voiding dysfunction, which was significantly less in the GH + E(2)-treated group than in the controls (P = 0.041).

CONCLUSION

This functional data suggest that the development of voiding dysfunction can be prevented by short-term administration of GH and GH + E(2) in our rat model. SERMs and E(2) alone seem to have no therapeutic effect.

Inhibitory effects of different ATP-sensitive potassium channel openers on electrically generated and carbachol-induced contractions of porcine and human detrusor muscle

The inhibitory effects of different potassium channel openers (PCOs) on electrically generated and carbachol-induced contractions of porcine and human detrusor muscle were examined. PCOs could be an interesting substance class for treatment of detrusor overactivity. Experiments were performed on muscle strips suspended in a tissue bath. Human tissue originated from patients who underwent total cystectomy. The concentration-relaxation curves of the first-generation PCOs cromakalim and pinacidil and the untypical PCO minoxidil were performed using carbachol-precontracted detrusor muscle strips of pigs and humans. Additionally, the inhibitory effects of cromakalim, pinacidil and minoxidil on electrically generated contractions of porcine detrusor muscle were examined. Furthermore, the inhibitory effect of the second-generation, bladder-selective PCO ZM 226600 on electrically generated contractions of the human detrusor muscle was determined. Frequency-response curves were performed before and after incubation with one PCO used in two different concentrations. In humans, cromakalim and pinacidil led to a maximum decrease of 73.5 and 68.4% and showed mean pD2 values of 6.65 and 5.5, respectively. In pigs, cromakalim and pinacidil led to a maximum decrease of 90.6 and 93.6% and showed mean pD2 values of 6.39 and 5.01, respectively. Minoxidil did not significantly decrease the precontraction at the highest used concentration in both species. Cromakalim exhibited the biggest inhibitory effect being significant at 10(-5) and 10(-6) M. Pinacidil showed only a significant inhibitory effect at 10(-5) M which was smaller than that of cromakalim. At 3 x 10(-6) M only a very small effect occurred at 1 Hz. Minoxidil did not inhibit the contractions at both examined concentrations except for a very small effect at 1 Hz. In humans, ZM 226600 exhibited at 10(-6) and 10(-5) M a significant inhibitory effect. At 10(-7) M it was only significant at one frequency.

The effects of anticholinergic drugs on attention span and short-term memory skills in children

AIMS

Studies have shown cognitive problems in adults treated with anticholinergics. It is unclear if children are also susceptible to anticholinergic adverse effects. This study evaluates the effects of long-acting oxybutynin and tolterodine on short-term memory and attention in children with urgency and urge incontinence.

METHODS

Children with urgency or urge incontinence were recruited to take part in a prospective, randomized double-blinded placebo controlled trial using long-acting oxybutynin or tolterodine. Patients underwent a baseline test of their memory/recall ability and attention span using a standardized developmental/neuropsychological assessment tool. They were then randomized to either medication or placebo with retesting in 2 weeks, at which time they were crossed. They were retested after the second 2 weeks.

RESULTS

Fourteen children (9 boys and 5 girls), ranging in age from 5 to 11 (M = 7.7) participated in the study. Attention and memory scores increased over time in all children, however, the analyses showed no significant negative effects of anticholinergic medications on attention or memory. Indeed, though not statistically significant, trends were for improvement in test scores in both areas.

CONCLUSIONS

Our results in a double blinded cross-over trial suggest that long-acting oxybutynin and tolterodine do not have a deleterious effect on children's attention and memory. Other cognitive functions may be affected.

Relaxation of human detrusor muscle by selective beta-2 and beta-3 agonists and endogenous catecholamines

OBJECTIVES

The goal of this study was to identify potent relaxant agents of the human detrusor muscle. Therefore, the relaxant effects of different selective beta (beta)-adrenoceptor agonists were examined. Also, the relaxant effects of the endogenous catecholamines were investigated to functionally characterize the beta-adrenoceptor subtype mainly responsible for adrenergic-mediated relaxation in the detrusor muscle of humans.

METHODS

Experiments were performed on muscle strips of human detrusor suspended in a tissue bath. The tissue originated from patients who had undergone total cystectomy. The selective beta3-agonists BRL 37344, ZD 7114, and CGP 12177, the selective beta2-agonists terbutaline and clenbuterol, and the nonselective beta-agonist isoprenaline were investigated. Concentration-relaxation curves of the catecholamines were performed to determine the rank order of potency.

RESULTS

The maximal relaxation induced by BRL 37344, ZD 7114, and CGP 12177 was 36%, 39%, and 37%, respectively. The corresponding pD2 values were 6.73, 4.82, and 6.09, respectively. Terbutaline and clenbuterol induced a maximal relaxation of 48% and 27%, and their pD2 value was 4.97 and 5.34, respectively. Isoprenaline, adrenaline, and noradrenaline induced a maximal relaxation of 72%, 58%, and 79%, respectively. The corresponding pD2 values were 6.18, 6.16, and 6.09, respectively. Because their differences were not significant, no rank order of potency was determined.

CONCLUSIONS

Beta-adrenergic agonists are potent relaxant agents of the human detrusor muscle in vitro. Both beta2 and beta3-adrenoceptors contribute to adrenergic-mediated relaxation. Our results point to a slightly greater role for the beta3-receptor in human detrusor muscle.

Relaxant effects of beta-adrenergic agonists on porcine and human detrusor muscle

AIM

Relaxant effects of different beta-adrenoceptor agonists on porcine and human detrusor were examined. Thus, the beta-adrenoceptor subtype mainly responsible for relaxation in the detrusor muscle of pigs was characterized. Additionally, different effects of several beta-agonists in both species were shown.

METHODS

Experiments were performed on muscle strips of porcine and human detrusor suspended in a tissue bath. The relaxant effects of the non-selective beta-agonist isoprenaline, the selective beta2-agonists procaterol, salbutamol and the selective beta3-agonists BRL 37344, CL 316 243 and CGP 12177 on potassium-induced contraction were investigated. The inhibitory effect of different substances on the maximum contraction and the rank order of potency for endogenous catecholamines was determined in pigs. Furthermore, concentration-relaxation curves were performed for pigs and humans.

RESULTS

Pigs: In the pre-treatment experiments isoprenaline and procaterol showed similar effects. The concentration-response experiments showed that the maximum relaxation induced by procaterol and salbutamol was more than 90%, not significantly different from isoprenaline, whereas the maximum relaxations of CL 316 243, BRL 37344 and CGP 12177 amounted to 68, 70 or 30%, respectively. Rank order of potencies was isoprenaline > or = adrenaline > noradrenaline. Humans: Isoprenaline, procaterol, salbutamol and CL 316 243 showed a maximum relaxation of 80, 41, 24 and 35% and pD2 values of 6.24, 5.65, 5.48 and 5.55, respectively.

CONCLUSION

Beta2-receptors play a main functional role in mediating relaxation of porcine detrusor. Selective beta2- and beta3-agonists similarly relax the human detrusor. Effects were smaller compared with the pig.

Effect of herbal extract mixture on menopausal urinary incontinence in ovariectomized rats

The decline of estrogen production after menopause is contributing factor to urinary incontinence (UI), and particularly stress urinary incontinence (SUI). We determined the preventive effects of herbal extract mixture (HEM) on UI in ovariectomized Sprague Dawley rats. Female 9-weeks old rats were ovariectomized and treated with HEM (2.2, 11, or 55 mg/kg/day) for 8 weeks. The index of urinary bladder weight to body weight in the HEM and non-ovariectomized and non-treated (SHAM) groups were slightly higher than the ovariectomized, non-treated group (OVX). The contraction index of acetylcholine to KCl on detrusor smooth muscle strips in the HEM groups showed a dose-dependent recovery. HEM treatment also significantly improved collagen levels, as shown by Masson trichrome staining, as well as hydroxyproline levels in the urinary bladder. Serum estradiol levels in the HEM groups were higher than the OVX group. In conclusion, HEM increased estradiol levels in serum and improved factors related to urinary incontinence. The improvements in estradiol levels were related to changes in urinary incontinence.

Synthesis and Structure−Activity Studies on N-[5-(1H-Imidazol-4-yl)-5,6,7,8-tetrahydro-1-naphthalenyl]methanesulfonamide, an Imidazole-Containing α1A-Adrenoceptor Agonist

Structure-activity studies were performed on the alpha(1A)-adrenoceptor (AR) selective agonist N-[5-(1H-imidazol-4-yl)-5,6,7,8-tetrahydro-1-naphthalenyl]methanesulfonamide (4). Compounds were evaluated for binding activity at the alpha(1A), alpha(1b), alpha(1d), alpha(2a), and alpha(2B) subtypes. Functional activity in tissues containing the alpha(1A) (rabbit urethra), alpha(1B) (rat spleen), alpha(1D) (rat aorta), and alpha(2A) (rat prostatic vas deferens) was also evaluated. A dog in vivo model simultaneously measuring intraurethral pressure (IUP) and mean arterial pressure (MAP) was used to assess the uroselectivity of the compounds. Many of the compounds that were highly selective in vitro for the alpha(1A)-AR subtype were also more uroselective in vivo for increasing IUP over MAP than the nonselective alpha(1)-agonists phenylpropanolamine (PPA) (1) and ST-1059 (2, the active metabolite of midodrine), supporting the hypothesis that greater alpha(1A) selectivity would reduce cardiovascular side effects. However, the data also support a prominent role of the alpha(1A)-AR subtype in the control of MAP.

A randomized crossover study to evaluate Ro 115-1240, a selective alpha1A/1L-adrenoceptor partial agonist in women with stress urinary incontinence

OBJECTIVES

To investigate the potential therapeutic benefits of the selective alpha1A/1l-adrenoceptor partial agonist Ro 115-1240 in women with mild-to-moderate stress urinary incontinence (SUI).

PATIENTS AND METHODS

Thirty-seven women with mild-to-moderate SUI were enrolled in a randomized, placebo-controlled crossover study. Patients received 1.5 mg Ro 115-1240 twice daily or matching placebo for 2 or 4 weeks. Voiding diaries were used to record the number of SUI episodes, urge incontinence episodes and pads used. Sitting blood pressures and heart rate were recorded at each visit.

RESULTS

Ro 115-1240 was associated with a significantly lower mean weekly number of SUI episodes than placebo (8.4 vs 6.0; P= 0.0079), a 28% relative improvement over placebo. There was also a significantly lower mean number of pads used and wet pads changed/week with Ro 115-1240 than with placebo (P = 0.0055 and 0.0066, respectively). The most frequently reported treatment-emergent adverse events were scalp tingling, headache, chills, piloerection, and pruritus. Generally these events were transient and mild to moderate. There was a slightly lower mean sitting heart rate with Ro 115-1240 than with placebo, but no difference in mean systolic or diastolic blood pressure between treatments.

CONCLUSIONS

This study suggests that selective alpha1A/1l-adrenoceptor partial agonists have the potential to improve the symptoms of SUI with little or no cardiovascular effect. These results are encouraging and a randomized controlled trial of Ro 115-1240 in a larger population with SUI is warranted to substantiate these findings.

Autonomic Nervous System Dysfunction in Parkinson's Disease

Autonomic nervous system (ANS) dysfunction is common in Parkinson's disease (PD), affects 70% to 80% of patients, and causes significant morbidity and discomfort. Autonomic nervous system dysfunction symptoms in PD include sexual dysfunction, swallowing and gastrointestinal disorders, bowel and bladder abnormalities, sleep disturbances, and derangements of cardiovascular regulation, particularly, orthostatic hypotension. Autonomic nervous system dysfunction in PD may be caused by an underlying degenerative process that affects the autonomic ganglia, brainstem nuclei, and hypothalamic nuclei. Anti-parkinsonian medications can cause or worsen symptoms of ANS dysfunction. The care of a PD patient with ANS dysfunction relies on its recognition and directed treatment, including coordinated care between the neurologist and appropriate subspecialist. Pharmacotherapy may be useful to treat orthostasis, gastrointestinal, urinary, and sexual dysfunction.

Effect of muscarinic antagonists on micturition pressure measured by cystometry in normal, conscious rats

OBJECTIVES

To establish an in vivo model to screen new muscarinic antagonists for the treatment of overactive urinary bladder and to calculate the respective ID(50) values.

METHODS

The conscious rat cystometry model was modified to determine a complete dose-response curve in each animal. Spontaneous micturition was induced by infusion of room-temperature saline into rat bladders at a constant rate of 12 mL/hr. Cumulative doses of muscarinic antagonists administered in the femoral vein caused dose-dependent inhibition of the urinary bladder contraction measured as the micturition pressure. In addition, the in vitro pK(B) values for atropine, PNU-200577 (DD01), tolterodine, oxybutynin, and terodiline were determined in carbachol-contracted rat bladder strips.

RESULTS

The rank order of the in vivo ID(50) values were atropine (14 +/- 4 nmol/kg), PNU-200577 (22 +/- 12 nmol/kg), tolterodine (94 +/- 20 nmol/kg), oxybutynin (175 +/- 89 nmol/kg), darifenacin (236 +/- 144 nmol/kg), desethyloxybutynin (313 +/- 209 nmol/kg), propiverine (4561 +/- 2079 nmol/kg), and terodiline (18,339 +/- 5348 nmol/kg). Tolterodine and PNU-200577 caused a parallel shift of the in vitro concentration-response curve to the right and did not alter the maximal contraction. The ID(50) values correlated significantly with the in vitro rat pK(B) and human bladder pA(2) values.

CONCLUSIONS

The present results suggest that the rat cystometry model can be used in in vivo screening for new muscarinic antagonists.

Preliminary study of the safety and efficacy of extended-release oxybutynin in children

OBJECTIVES

To test the safety and efficacy of extended-release oxybutynin in children with bladder dysfunction. The efficacy of oxybutynin in children has been limited by side effects. A new extended-release formulation of oxybutynin has some benefits versus traditional oxybutynin but has never been evaluated in children.

METHODS

A retrospective study was performed on 25 children who had been treated with extended-release oxybutynin. Fourteen had neurogenic bladder dysfunction and 11 had urinary frequency and urgency and urge incontinence but no neurologic abnormalities. Patients and families were asked to semiquantitatively (0 to 10 grading with 10 = severe) assess the effects of the medication on efficacy, as well as side effects and compliance with medication schedules.

RESULTS

All 25 patients had improvement in incontinence and/or voiding dysfunction on extended-release oxybutynin. Twelve (48%) experienced no side effects. Of the 13 who did, 10 complained of dry mouth (grade 4.6 plus minus 0.5), 4 had constipation (grade 5.8 plus minus 1.8), 4 had heat intolerance (grade 5.1 plus minus 0.9), and 3 had drowsiness (grade 5.3 plus minus 2.4). Of patients previously treated with oxybutynin, the extended-release oxybutynin was equally or more efficacious and had the same or fewer side effects, especially less dry mouth. Families reported much better patient compliance with the medication regimen using extended-release oxybutynin compared with oxybutynin. Patient and family satisfaction was very high, and 21 of 25 have continued using the medication.

CONCLUSIONS

Extended-release oxybutynin is safe and efficacious in children. In this preliminary evaluation, it had benefits over traditional, immediate-release oxybutynin.