Motor and sensory responses after percutaneous tibial nerve stimulation in multiple sclerosis patients with lower urinary tract symptoms treated in daily practice.

BACKGROUND AND PURPOSE: Posterior tibial nerve stimulation (PTNS) is an effective treatment option for lower urinary tract symptoms (LUTS) in multiple sclerosis (MS) patients. METHODS: Patients with MS and LUTS unresponsive to medical treatment received PTNS for 12 weeks after saline urodynamics to evaluate the prevalence of motor, sensory and combined responses during PTNS and to determine whether the type of response can predict treatment outcome. LUTS were also assessed using a 3-day bladder diary, patient perception of bladder condition (PPBC) questionnaire, patient perception of intensity of urgency scale (PPIUS), Kings Health QOL questionnaire (KHQ) and Overactive Bladder Questionnaire (OAB-q) before and after treatment. Patients were considered as "responders" if they reported an improvement >50% in their LUTS according to the PPBC. Sensory, motor and combined sensory/motor responses were compared between responders and non-responders. RESULTS: Eighty-three patients were included. 61% (51/83) of patients were responders. Sensory, motor and combined sensory/motor responses were found in 64% (53/83), 6% (5/83) and 30% (25/83) of patients respectively. A sensory response alone, or in combination with a motor response, was better associated with a successful outcome than the presence of a motor response alone (P = 0.001). CONCLUSIONS: A sensory response, either alone or in combination with a motor response, is more frequent and seems to be better associated with a successful outcome of PTNS than motor response alone.

Changes in nerve growth factor level and symptom severity following antibiotic treatment for refractory overactive bladder.

INTRODUCTION AND HYPOTHESIS: Overactive bladder (OAB) has a multifactorial aetiology, and for some women symptoms may be associated with chronic urothelial inflammation secondary to bacterial colonisation. One marker of such inflammation may be urinary nerve growth factor (NGF). We hypothesised that for women with OAB and urothelial inflammation, urinary NGF would be reduced following antibiotic therapy. METHODS: Women with overactive bladder and urodynamic diagnosis of detrusor overactivity who were refractory to anticholinergics, and had histological evidence of urothelial inflammation were treated with a 6-week course of rotating antibiotics. Urinary NGF was measured by ELISA before and after treatment. Three-day bladder diaries, the Patients' Perception of Intensity of Urgency Scale, the King's Health Questionnaire and the Patients' Perception of Bladder Condition questionnaire were used to assess subjective and objective outcomes of therapy. RESULTS: Thirty-nine women with refractory DO were recruited. The NGF levels decreased significantly after antibiotic therapy (Wilcoxon signed rank test; p = 0.015). There were significant improvements in daytime frequency, nocturia and urgency (p < 0.05), and 74 % of women reported improvement in perception of their bladder condition. CONCLUSIONS: Urinary NGF is responsive to antibiotic therapy. Women with refractory overactive bladder and elevated NGF may benefit from antibiotic treatment.

Systematic review of the relationship between bladder and bowel function: implications for patient management.

BACKGROUND: The complex relationship between bladder and bowel function has implications for treating pelvic disorders. In this systematic review, we discuss the relationship between bladder and bowel function and its implications for managing coexisting constipation and overactive bladder (OAB) symptoms. METHODS: Multiple PubMed searches of articles published in English from January 1990 through March 2011 were conducted using combinations of terms including bladder, bowel, crosstalk, lower urinary tract symptoms, OAB, incontinence, constipation, hypermotility, pathophysiology, prevalence, management and quality of life. Articles were selected for inclusion in the review based on their relevance to the topic. RESULTS: Animal studies and clinical data support bladder-bowel cross-sensitization, or crosstalk. In the rat, convergent neurons in the bladder and bowel as well as some superficial and deeper lumbosacral spinal neurons receive afferent signals from both bladder and bowel. On a functional level, in animals and humans, bowel distention affects bladder activity and vice versa. Clinically, the bladder-bowel relationship is evident through the presence of urinary symptoms in patients with irritable bowel syndrome and bowel symptoms in patients with acute cystitis. Functional gastrointestinal disorders, such as constipation, can contribute to the development of lower urinary tract symptoms, including OAB symptoms, and treatment of OAB with antimuscarinics can worsen constipation, a common antimuscarinic adverse effect. The initial approach to treating coexisting constipation and OAB should be to relieve constipation, which may resolve urinary symptoms. CONCLUSIONS: The relationship between bladder and bowel function should be considered when treating patients with urinary symptoms, bowel symptoms, or both.

Validation study of the Self-Assessment Goal Achievement (SAGA) questionnaire for lower urinary tract symptoms.

BACKGROUND: Patients' treatment goals for overactive bladder (OAB) and other lower urinary tract symptoms (LUTS) may not be aligned with their healthcare provider's goals. Successful management of OAB symptoms is improved by individualised treatment plans with attainable treatment goals. Goal attainment setting may facilitate patient-provider interaction and the development of a personalised treatment plan based on realistic, individual goals, thereby increasing patient satisfaction and therapeutic outcomes. The purpose of this study was to validate the utility of the Self-Assessment Goal Achievement (SAGA) questionnaire for LUTS in helping patients identify and achieve realistic treatment goals. METHODS: The 2-module SAGA questionnaire consists of nine prespecified (fixed) items and five open-ended items for goal identification and ranking (baseline module) and goal achievement rating (follow-up module). Adult patients in the United States (n = 104) seeking treatment for LUTS, including symptoms of OAB, completed the SAGA baseline module, micturition diary, other patient-reported outcome measures (PROs), and discussed their urinary goals with a clinician at baseline. The SAGA follow-up module was completed 2-4 months later. SAGA was validated based on analyses of face, concurrent, known-groups, and convergent validity and item distribution. RESULTS: Among the nine fixed goals of SAGA, four were ranked as very important by > 50% of patients (i.e. reduce night-time frequency, daytime frequency, urine leakage, urgency). Most patients did not change the importance level of their goals after discussion with their healthcare provider. Pearson correlations between SAGA, diary variables and PRO scores were generally of low to moderate strength. The global mean (SD) follow-up SAGA T-score was 32.54 (12.54), indicating that overall goal attainment was not achieved after 3 months. The goal attainment score was significantly different between groups differing in symptom severity, health-related quality of life, bladder control and continence status. CONCLUSIONS: The results support the validity of SAGA as a measure of patients' goals and goal achievement for the treatment of LUTS, including symptoms of OAB. SAGA may improve healthcare provider-patient interactions and treatment outcomes in clinical practice.

Mirabegron for the treatment of overactive bladder: a prespecified pooled efficacy analysis and pooled safety analysis of three randomised, double-blind, placebo-controlled, phase III studies.

INTRODUCTION: To examine pooled efficacy data from three, large phase III studies comparing mirabegron (50 and 100 mg) with placebo, and pooled safety data including additional mirabegron 25 mg and tolterodine extended release (ER) 4 mg results. METHODS: This prespecified pooled analysis of three randomised, double-blind, placebo-controlled, 12-week studies, evaluated efficacy and safety of once-daily mirabegron 25 mg (safety analysis), 50 or 100 mg (efficacy and safety analyses) and tolterodine ER 4 mg (safety analysis) for the treatment of symptoms of overactive bladder (OAB). Co-primary efficacy measures were change from baseline to Final Visit in the mean number of incontinence episodes/24 h and mean number of micturitions/24 h. Key secondary efficacy end-points included mean number of urgency episodes/24 h and mean volume voided/micturitions, while other end-points included patient-reported outcomes according to the Treatment Satisfaction-Visual Analogue Scale (TS-VAS) and responder analyses [dry rate (posttreatment), ≥ 50% reduction in incontinence episodes/24 h, ≤ 8 micturitions/24 h (post hoc analysis)]. The safety analysis included adverse event (AE) reporting, laboratory assessments, ECG, postvoid residual volume and vital signs (blood pressure, pulse rate). RESULTS: Mirabegron (50 and 100 mg once daily) demonstrated statistically significant improvements compared with placebo for the co-primary end-points, key secondary efficacy variables, TS-VAS and responder analyses (all comparisons p < 0.05). Mirabegron is well tolerated and demonstrates a good safety profile. The most common AEs (≥ 3%) included hypertension, nasopharyngitis and urinary tract infection (UTI); the incidence of hypertensive events and UTIs decreased with increasing dose. For mirabegron, the incidence of the bothersome antimuscarinic AE, dry mouth, was at placebo level and of a lesser magnitude than tolterodine. CONCLUSION: The efficacy and safety of mirabegron are demonstrated in this large pooled clinical trial dataset in patients with OAB.

The treatment of lower urinary tract symptoms in patients with multiple sclerosis: a systematic review.

This is a systematic review on the treatment of lower urinary tract symptoms (LUTS) in patients with multiple sclerosis (MS). The heterogeneity of the outcome criteria did not allow a meta-analysis of the published evidence. In the last few decades, the therapeutic options for neurogenic bladder dysfunction have broadened. Despite this, no consensus has been reached as to the management of LUTD and LUTS in patients with MS, and the subject remains controversial. Bladder dysfunction is common in MS, affecting 80 %-100 % of patients during the course of the disease. Several studies have shown that urinary incontinence has a severe effect on patients' quality of life, with 70 % of patients classifying the impact bladder symptoms had on their life as "high" or "moderate." Moreover, the progressive feature of MS makes its treatment complex, since any achieved therapeutic result may be short-lived, with the possibility that symptoms will recur or develop de novo.

A comparison study of two lower urinary tract symptoms screening tools in clinical practice: the B-SAQ and OAB-V8 questionnaires.

Lower urinary tract symptoms (LUTS) have a detrimental effect on quality-of-life (QoL). However, sufferers are often reluctant to seek help. Screening for LUTS will identify patients with bothersome symptoms who may benefit from treatment and allow patients to self-assess their symptoms and the need for medical intervention, potentially saving costly medical time and reducing long-term morbidity. The aim of this study was to compare the value of two validated questionnaires: the Bladder Control Self Assessment Questionnaire (B-SAQ) and the Overactive Bladder Awareness Tool (OAB-V8) as screening questionnaires in clinical practice. A total of 223 women were recruited prospectively from three centres. Participants completed both questionnaires in the waiting area prior to assessment by a clinician, who completed a symptom evaluation sheet. Data were analysed using receiver operating characteristic curves. Both the B-SAQ and the OAB-V8 performed well in detecting symptoms of OAB and mixed urinary symptoms. The B-SAQ performed better in detecting symptoms of stress incontinence than the OAB-V8. The opportunity to screen for haematuria should never be missed and this is an important omission from the OAB-V8.

Percutaneous posterior tibial nerve stimulation as an effective treatment of refractory lower urinary tract symptoms in patients with multiple sclerosis: preliminary data from a multicentre, prospective, open label trial.

BACKGROUND: Percutaneous tibial nerve stimulation (PTNS) has been proposed as a new, minimally invasive neuromodulation technique to treat lower urinary tract symptoms (LUTS). OBJECTIVE: To evaluate efficacy, safety and impact on quality of life (QoL) of PTNS on patients with multiple sclerosis (MS) who have LUTS. METHODS: 21 patients (5 men, 16 women) with MS and LUTS unresponsive to anticholinergics were treated with 12 sessions of PTNS. Assessment of LUTS was by validated, self-administered chart and questionnaires, testing the subjective and objective relevance of LUTS for patients and their impact on QoL before and after treatment; the mean post-micturition residual was assessed by trans-abdominal ultrasound scanning. Analysis was by intention to treat. RESULTS: There was a significant reduction of daytime frequency (from 9 to 6, p = 0.04), nocturia (from 3 to 1, p = 0.002) and mean post-micturition residual (from 98 ± 124 ml to 43 ± 45 ml, p = 0.02). The mean voided volume increased from 182 ± 50 ml to 225 ± 50 ml (p = 0.003). Eighty-nine percent of patients reported a treatment satisfaction of 70%. Significant improvement in QoL was seen in most domains of the King's Health QoL questionnaire (p < 0.05). No adverse events were reported. CONCLUSIONS: PTNS is an effective, safe and well-tolerated treatment for LUTS in patients with MS.

Rectal distension: the effect on bladder function.

AIMS: To assess how rectal distension affects urodynamics parameters and diagnosis. METHODS: Thirty women underwent filling cystometry with a rectal balloon inserted and filled with 150 ml of normal saline and repeated without the balloon distended. The volume at which first desire, strong desire and bladder capacity were reported by the women was recorded as well as urodynamics diagnosis. Women were randomized, using the closed envelope method, into having the rectal balloon distended during the first or during the second filling phase. Women with any bowel disease, history of bleeding per rectum were excluded, or women with any contraindication to undergoing urodynamics, or insertion of a device per rectum. All women of a reproductive age underwent pregnancy test and excluded if found to be pregnant. RESULTS: Thirty patients were recruited, 16 reported mixed urinary incontinence (53%), 5 (17%) had isolated overactive bladder (OAB) symptoms and 9 (30%) reported isolated stress urinary incontinence. Patients with distended rectum had statistically significant lower bladder volumes at which first (46% reduction) and strong desire (33% reduction) was felt and reduced maximum bladder capacity (26% reduction) when compared to the rectum being undistended. In four patients (13%) with a history of OAB a diagnosis of detrusor overactivity was found with the rectum was distended but not when the rectum was empty. CONCLUSION: Rectal distension alters bladder sensation and in some cases urodynamics diagnosis.

Ultrasound measurement of bladder wall thickness is associated with the overactive bladder syndrome.

AIMS: To assess the relationship between mean bladder wall thickness and components of the overactive bladder (OAB syndrome). METHODS: Women attending urogynaecology clinic was categorized into overactive bladder syndrome, stress urinary incontinence (SUI), and mixed urinary continence (MUI) according to International Continence Society (ICS) definitions based on symptom history. Women completed a bladder diary, visual analog score (VAS) for urgency, and the mean bladder wall thickness (BWT) was determined. Comparison was made between the mean BWT and symptom history, daytime frequency, nocturia, VAS scores. RESULTS: Three hundred seventy-nine women were recruited to the study with a mean age of 56 years (range: 24-92 years). The mean bladder wall thickness did not show any age-related difference. Of these women 138/379 (36%) reported overactive bladder symptoms (mean BWT = 5.6 mm) 75/379 (20%) gave a history of stress urinary incontinence (mean BWT = 4.7 mm), and 166/379 (44%) had mixed urinary incontinence (mean BWT = 5.4). Women with nocturia >1 had mean BWT 5.6 mm, with nocturia <1 a mean BWT 4.9 mm. Women with daytime frequency >7 had mean BWT 5.7 mm and those <7 had mean BWT 5.1 (P < 0.001). Women with a mean BWT of ≤5 mm had a mean VAS score lower than women with a BWT >5 mm (P < 0.001). CONCLUSIONS: Mean BWT is associated with a symptom history of OAB and MUI, higher daytime and nightime frequency, and higher VAS scores.

Pre-operative opening detrusor pressure is predictive of detrusor overactivity following TVT in patients with pre-operative mixed urinary incontinence.

AIMS: To determine if specific pre-operative urodynamic parameters could predict detrusor overactivity following TVT in patients with urodynamic mixed incontinence. METHODS: Notes of women with detrusor overactivity (DO) and urodynamic stress incontinence (USI) before undergoing tension-free vaginal tape (TVT) surgery were retrospectively reviewed. Patients underwent clinical evaluation pre-operatively including history, examination, and conventional urodynamic studies and were treated with pelvic floor exercises and anti-cholinergic medication. Those with persistent stress urinary incontinence (SUI) underwent TVT. Patients were re-assessed after at least 6 months post-operatively. Pre- and post-operative opening and closing detrusor pressure, and detrusor pressure at maximum flow were recorded retrospectively from pre-operative urodynamics traces by two clinicians independently and compared to the patients' post-operative symptoms and urodynamic diagnosis. RESULTS: Fifty-one women were reviewed. Forty-six of the 51 attended follow-up and 35/51 agreed to conventional urodynamic studies. Seventeen of the 35 reported OAB symptoms, and 18/35 were asymptomatic. Nineteen of the 35 women had DO and 16/35 had normal urodynamic studies (NUDS). The median pre-operative opening detrusor pressure was higher in women with overactive bladder symptoms post-operatively. The median pre-operative opening detrusor pressure in women with DO post-operatively was 33.0 cmH(2)O and the median pre-operative opening detrusor pressure in those with NUDS post-operatively was 16 cmH(2)O (15.0-23.0 cmH(2)O) (P < 0.05 Mann-Whitney U-test). CONCLUSIONS: Higher numbers of patients are required to demonstrate the value of opening detrusor pressure in predicting post-operative overactive bladder symptoms. Opening detrusor pressure is predictive of post-operative DO after TVT.

Reference intervals of gestational sac, yolk sac and embryo volumes using three-dimensional ultrasound.

OBJECTIVES: To create reference intervals of gestational sac volume (GSV), yolk sac volume (YSV), embryo volume (EV), crown-rump length (CRL) and gestational sac diameter (GSD) in the first trimester of pregnancy using three-dimensional ultrasound. METHODS: Women in the first trimester of pregnancy were invited to participate in the study. Inclusion criteria were well-established dates, and that the women were non-smokers and healthy, without any medical disorders. Three-dimensional ultrasound volumetric data (GSV, YSV, EV) were collected together with standard two-dimensional measurements of CRL and GSD. For each measurement separate regression models were fitted to estimate the mean and SD at each gestational age. The 5(th), 50(th) and 95(th) centiles were derived using a combination of these regression models. RESULTS: One hundred and sixty-six women at between 6 and 12 weeks' gestation were scanned once. The mean ( +/- SD) maternal age was 29.4 ( +/- 5) years. There were no miscarriages and no congenital abnormalities were noted. Mean gestational age at delivery was 39.3 ( +/- 1.4) weeks and mean birth weight was 3.3 ( +/- 0.4) kg. The CRL centiles fitted a cubic model and the GSD centiles fitted a linear model. The centiles for YSV fitted a quadratic model on the modified log-transformed data. The centiles for GSV and EV were modeled using quantile regression. CONCLUSION: Reference intervals and centile charts for first-trimester GSV, YSV and EV have been created in addition to CRL and GSD using rigorous methodology.

Do colour and personality influence treatment seeking behaviour in women with lower urinary tract symptoms? A prospective study using the short Luscher colour test.

Lower urinary tract symptoms (LUTS) are common and affect quality of life. The influence of personality on the patients' decision to seek help is poorly understood. The aim of this study was to identify personality traits which may influence womens' decision to seek help for LUTS using the short Luscher colour test (LCT). Participants completed two validated questionnaires prior to taking part in the LCT. Symptomatic non-treatment seekers were identified as impatient. Women seeking help for LUTS were identified as impatient, restless, authoritative and determined individuals. Asymptomatic women were identified as sensitive individuals who have strong ideals and desire their own way. Further studies are required to improve knowledge about the influence of personality on treatment seeking behaviour in women with LUTS.

A cost-effectiveness analysis of delayed sphincteroplasty for anal sphincter injury.

OBJECTIVE: Anal-sphincter injury may result in faecal incontinence. Sphincteroplasty is usually performed as a primary (immediate) procedure. Delayed sphincteroplasty (DS) can be performed if there is significant trauma or soiling, if the primary procedure has failed, and if the injury was not recognized initially. This study aimed to determine the cost to patient and health service in the event a DS is performed. METHOD: Patients with anal-sphincter-injury who underwent primary sphincteroplasty (PS)/DS were identified from the published literature (primary, n = 103; delayed, n = 777) using Medline, Embase, Ovid and Cochrane databases for studies published between 1976 and 2006. Studies included described at least one of the measured outcomes--probability of functional success/failure and quality of life (QOL). An economic model was constructed and decision analysis performed using a decision tree based on a Markov process. Main outcomes were quality-adjusted-life-years (QALYs) gained from each strategy, costs incurred and incremental cost-effectiveness ratio (ICER) over a 10- and 15-year time horizon. RESULTS: Over 10 years, primary sphincteroplasty (PS) produced a gain of 5.72 QALYs for an estimated 2750 pounds, giving an ICER of 487 pounds per QALY. DS produced a gain of 3.73 QALYs for a cost of 2667 pounds, giving an ICER of 719 pounds per QALY. Both procedures fell below the 10,000 pounds per QALY willingness-to-pay threshold, but PS produced the highest QALYs. Both procedures performed poorly beyond the 10-year mark. CONCLUSION: If DS has to be performed, the resultant cost is greater with concurrently lower QALYs gained. Successful PS substantially improves QOL and reduces overall cost-of-treatment.

Direct imaging of the pelvic floor muscles using two-dimensional ultrasound: a comparison of women with urogenital prolapse versus controls.

OBJECTIVE: To evaluate the anatomy of the levator ani muscle in women with urogenital prolapse versus matched controls without prolapse using real-time two-dimensional (2-D) ultrasound. DESIGN: Prospective observational study. SETTING: Tertiary referral urogynaecology unit. POPULATION: Forty-three women with pelvic organ prolapse (POP) and 24 women (controls) attending a gynaecology clinic without prolapse. METHODS: All participants completed a standardised symptom questionnaire. MAIN OUTCOME MEASURES: The morphology of the vagina and paravaginal tissue was recorded at different levels. The thickness of the levator ani and the hiatal area were measured at rest. Reproducibility of the method was assessed by repeated measurements to assess intra-observer variability and inter-observer variability. RESULTS: This method showed good intra-observer and inter-observer reproducibility and reliability. In controls, the pubococcygeus muscle showed more regular echogenicity with no evidence of trauma, whereas in women with prolapse the muscle had mixed echogenicity. (P = 0.002). The mean thickness of the pubococcygeus did not differ between groups. The levator hiatal area was significantly larger in women with pelvic floor prolapse versus controls (17.8 cm2 versus 13.5 cm2, P < 0.001). This increase in hiatal area positively and significantly correlated with prolapse severity (P < 0.001). CONCLUSIONS: Morphology and hiatal area can be reliably imaged using 2-D ultrasound. Prolapse was related to changes in pelvic floor morphology and increased levator hiatal area. The use of 2-D ultrasound provides an important insight into the pathophysiology of prolapse.

Imaging the urethral sphincter with three-dimensional ultrasound.

OBJECTIVE: To image the striated urethral sphincter (rhabdosphincter) using three-dimensional ultrasound and to compare its size in women with genuine stress incontinence and continent controls. METHODS: Women with no previous continence or prolapse surgery had transvaginal sonography using a 7.5-MHz mechanical sector endoprobe with real-time and three-dimensional facilities. Three perpendicular planes were displayed simultaneously on the screen. Manipulation of the stored images allowed detailed morphologic assessment of the urethra at different levels using several parallel cross-sectional planes along its length. The length, thickness, and volume of the rhabdosphincter were measured. RESULTS: Forty-six women with genuine stress incontinence (27-73 years, mean 48) and 48 continent controls (23-76 years, mean 49) were studied. In the transverse plane, the inner part of the urethra, which consists of urothelium and smooth muscle, appeared hyperechogenic compared with the outer hypoechogenic ring of striated muscle. The two groups studied were not different in age and parity. Women with genuine stress incontinence, compared with continent controls, had a significantly shorter (mean +/- standard deviation 16.9 +/- 1.9 mm compared with 19.2 +/- 3.6 mm; P = .001), thinner (2.1 +/- 0.5 mm compared with 2.5 +/- 0.4 mm; P < .001), and smaller volume (0.8 +/- 0.2 mL compared with 1.2 +/- 0.2 mm; P < .001) of the striated urethral sphincter. There was a close correlation between the urethral sphincter volume and the degree of incontinence assessed on videocystourethrography (r = -.65, P < .001). CONCLUSION: Three-dimensional ultrasound allowed examination of the female urethra in planes that could not be visualized by conventional sonography. The rhabdosphincter had a smaller volume in women with genuine stress incontinence than in continent women.

Evidence available on the use of the selective ß3-adrenoceptor agonist mirabegron for the treatment of overactive bladder.

CONTEXT: Mirabegron, the selective ß3-adrenoceptor agonist, heralds the latest development for the treatment of overactive bladder (OAB). OBJECTIVE: To present the evidence available on the efficacy and tolerability of mirabegron and to discuss this treatment's potential in our setting. EVIDENCE ACQUISITION: We reviewed 11 studies conducted with mirabegron in patients with OAB (2 phase II, 9 phase III), all studies were compared to placebo with 6 studies also including tolterodine as an additional arm. Greater emphasis shall be given to the main phase III trials performed in Europe, the USA and Australia evaluating efficacy and safety after 12 weeks (NCT00662909, NCT00689104, NCT00912964) and safety after 12 months (NCT00688688). The combined analyses of these 12 week studies is also available, with emphasis on global efficacy (FAS), efficacy with regard to incontinence (FAS i) and safety (SAF). More than 50% of patients had previously discontinued anticholinergics medication for OAB, thus allowing us to obtain data on the effectiveness of mirabegron in patients already treated with anticholinergics. EVIDENCE SYNTHESIS: Mirabegron is an efficacious drug which presents a statistically significant reduction in the number of incontinence episodes and in urinary frequency as of 4 weeks, with a higher percentage of dry patients and a higher percentage of patients with reduction ≥50% in the number of incontinence episodes than placebo. The efficacy of mirabegron 50 and 100mg in the reduction of incontinence episodes occurs in de novo patients and who have received antimuscarinics, with adjusted mean difference and improvement in urinary frequency greater in treated patients. Its tolerability is very similar to placebo particularly for the adverse effects of the antimuscarinics (dry mouth, constipation and blurred vision). A minimal, non-clinically significant change is observed in systolic and diastolic blood pressure and pulse. Its efficacy is long-term. Mirabegron at the doses of 50 and 100mg presents an improvement versus placebo in patient satisfaction, health-related quality of life (HRQoL), symptom bother and patient's perception of bladder condition (PPBC). In the 12 week Phase III European study tolterodine delivered a lesser degree of improvement than mirabegron versus placebo in patient satisfaction, HRQoL, symptom bother and PPBC. CONCLUSIONS: Mirabegron is the first of a new class of compounds with a novel mechanism of action that is different to the antimuscarinics. It presents significant and clinically important efficacy in the treatment of the symptoms of OAB. It has advantages with regard to the results described by the patient in treatment satisfaction. Studies on its combined use with anticholinergics are ongoing.