Routine first-trimester pre-eclampsia screening and maternal left ventricular geometry

OBJECTIVE

Pre-eclampsia (PE) is a pregnancy complication associated with premature cardiovascular disease morbidity and mortality (i.e. before 60 years of age or in the first year postpartum). PE is associated with adverse left ventricular (LV) remodeling in the peri- and postpartum periods, an independent risk factor for cardiovascular disease. This study aimed to compare LV geometry by LV mass (LVM) and LVM index (LVMI) between participants with a high vs low screening risk for preterm PE in the first trimester.

METHODS

This was a prospective cohort study of singleton pregnancies between 11 + 0 and 13 + 6 weeks' gestation that underwent screening for preterm PE as part of their routine first-trimester ultrasound assessment at a tertiary center in London, UK, from February 2019 until March 2020. Screening for preterm PE was performed using the Fetal Medicine Foundation algorithm. Participants with a screening risk of ≥ 1 in 50 for preterm PE were classified as high risk and those with a screening risk of ≤ 1 in 500 were classified as low risk. All participants underwent two-dimensional and M-mode transthoracic echocardiography.

RESULTS

A total of 128 participants in the first trimester of pregnancy were included in the analysis, with 57 (44.5%) participants screened as low risk and 71 (55.5%) participants as high risk for PE. The risk groups did not vary in maternal age and gestational age at assessment. Maternal body surface area and body mass index were significantly higher in the high-risk group (all P < 0.05). The high-risk participants were significantly more likely to be Afro-Caribbean, nulliparous and have a family history of hypertensive disease in pregnancy as well as other cardiovascular disease (all P < 0.05). In addition, mean arterial blood pressure (P < 0.001), mean heart rate (P < 0.001), median LVM (130.06 (interquartile range, 113.62-150.50) g vs 97.44 (81.68-114.16) g; P < 0.001) and mean LVMI (72.87 ± 12.2 g/m2 vs 57.54 ± 12.72 g/m2 ; P < 0.001) were significantly higher in the high-risk group. Consequently, those in the high-risk group were more likely to have abnormal LV geometry (37.1% vs 7.0%; P < 0.001).

CONCLUSIONS

Early echocardiographic assessment in participants at high risk of preterm PE may unmask clinically healthy individuals who are at increased risk for future cardiovascular disease. Adverse cardiac remodeling in the first trimester of pregnancy may be an indicator of decreased cardiovascular reserve and subsequent dysfunctional cardiovascular adaptation in pregnancy. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Incidence of postpartum hypertension within 2 years of a pregnancy complicated by pre-eclampsia: a systematic review and meta-analysis

BACKGROUND

Women with a history of hypertensive disorders of pregnancy (HDP) are at increased long-term risk of cardiovascular disease. However, there has been increasing evidence on the same risks in the months following birth.

OBJECTIVES

This review aims to estimate the incidence of hypertension in the first 2 years after HDP.

SEARCH STRATEGY

MEDLINE, Embase and Cochrane databases were systematically searched in October 2019.

SELECTION CRITERIA

Observational studies comparing hypertension rate following HDP and normotensive pregnancies up to 2 years.

DATA COLLECTION AND ANALYSIS

A meta-analysis to calculate the odds ratio (OR) with a 95% confidence interval (CI) and a sub-group analysis excluding women with chronic hypertension were performed.

MAIN RESULTS

Hypertension was diagnosed within the first 2 years following pregnancy in 468/1646 (28.4%) and 584/6395 (9.1%) of the HDP and control groups, respectively (OR 6.28; 95% CI 4.18-9.43; I²  = 56%). The risk of hypertension in HDP group was significantly higher in the first 6 months following delivery (OR 18.33; 95% CI 1.35-249.48; I²  = 84%) than at 6-12 months (OR 4.36; 95% CI 2.81-6.76; I²  = 56%) or between 1-2 years postpartum (OR 7.24; 95% CI 4.44-11.80; I²  = 9%). A sub-group analysis demonstrated a similar increase in the risk of developing postpartum hypertension after HDP (OR 5.75; 95% CI 3.92-8.44; I²  = 49%) and pre-eclampsia (OR 6.83; 95% CI 4.25-10.96; I²  = 53%).

CONCLUSIONS

The augmented risk of hypertension after HDP is highest in the early postpartum period, suggesting that diagnosis and targeted interventions to improve maternal cardiovascular health may need to be commenced in the immediate postpartum period.

TWEETABLE ABSTRACT

The risk of hypertension within 2 years of birth is six-fold higher in women who experienced pre-eclampsia.

Long-term Safety and Efficacy of Mirabegron and Solifenacin in Combination Compared with Monotherapy in Patients with Overactive Bladder: A Randomised, Multicentre Phase 3 Study (SYNERGY II)

BACKGROUND

The long-term potential of solifenacin and mirabegron combination treatment for patients with overactive bladder (OAB) has not been previously assessed.

OBJECTIVES

To evaluate the safety and efficacy of solifenacin succinate 5mg plus mirabegron 50mg tablets (combination treatment) versus solifenacin or mirabegron monotherapy in patients with OAB over 12 mo.

DESIGN, SETTING, AND PARTICIPANTS

Randomised, double-blind, multicentre, phase 3 trial (SYNERGY II) of patients with "wet" OAB symptoms (urinary frequency and urgency with incontinence) for ≥3 mo. The study was conducted from March 2014 to September 2016; with 1829 patients randomised. The full analysis set was comprised of 1794 patients.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary objective was safety, measured as treatment-emergent adverse events (TEAEs). Efficacy was measured as the change from baseline to the end of treatment in the mean number of incontinence episodes/24h and micturitions/24h.

RESULTS AND LIMITATIONS

The median age was 60 yr (range 19-86 yr) and 1434 patients (80%) were female. Overall, 856 patients (47%) experienced ≥1 TEAE. TEAE frequency was slightly higher in the combination group (596 patients, 49%; mirabegron 126 patients, 41%; solifenacin 134 patients, 44%). Serious TEAEs were reported by 67 patients (3.7%); one was considered possibly treatment-related (mirabegron group, atrial fibrillation). Dry mouth was the most common TEAE (combination 74 patients, 6.1%; solifenacin 18 patients, 5.9%; mirabegron 12 patients, 3.9%). Combination therapy was statistically superior to mirabegron and solifenacin for the number of incontinence episodes (vs mirabegron: adjusted mean difference [AMD] -0.5, 95% confidence interval [CI] -0.7 to -0.2, p<0.001; vs solifenacin: AMD -0.1, 95% CI -0.4 to 0.1, p=0.002) and micturitions (vs mirabegron: AMD -0.5, 95% CI -0.8 to -0.2, p<0.001; vs solifenacin: AMD -0.4, 95% CI -0.7 to -0.1, p=0.004).

CONCLUSIONS

Mirabegron and solifenacin combination treatment for OAB symptoms was well tolerated over 12 mo and led to efficacy improvements over each monotherapy. This innovative combination is a treatment option that could become widely used in the clinic.

PATIENT SUMMARY

This study looked at the safety and efficacy of a combination of solifenacin succinate 5mg plus mirabegron 50mg tablets over 12 mo in patients with the overactive bladder (OAB) symptoms of increased urination frequency, heightened urgency to urinate, and unintentional passing of urine. We compared this treatment with solifenacin succinate 5mg or mirabegron 50mg alone, and found that the combination treatment was well tolerated by patients and led to greater improvements in symptoms. This novel combination could be an improved treatment option in the clinical setting for patients with OAB. This study is registered at ClinicalTrials.gov as NCT02045862.

Cardiovascular Safety of the β3 -Adrenoceptor Agonist Mirabegron and the Antimuscarinic Agent Solifenacin in the SYNERGY Trial

There have been concerns that treatment of overactive bladder with β₃ -adrenoceptor agonists may potentially have detrimental cardiovascular (CV) side effects. We evaluated the CV safety of mirabegron, a β₃ -adrenoceptor agonist, alone and in combination therapy with the antimuscarinic agent solifenacin. The SYNERGY trial was a multinational, multicenter, randomized, double-blind, parallel-group, placebo and active-controlled phase 3 trial. Patients were randomized to receive solifenacin 5 mg + mirabegron 50 mg (combination 5 + 50 mg), solifenacin 5 mg + mirabegron 25 mg (combination 5 + 25 mg), solifenacin 5 mg monotherapy, mirabegron 25 mg monotherapy, mirabegron 50 mg monotherapy, or placebo for a 12-week double-blind treatment period. A total of 3398 patients were included in the study. Mean changes from baseline to the end of therapy in ECG parameters were similar across treatment groups, although there was an increase in heart rate of 1 beat/minute in the mirabegron treatment groups. There were no clinically meaningful differences in change from baseline in QTcF between monotherapies and placebo and between monotherapies and combination therapy. There were very few major CV events: 1 of 853 (0.1%) with a nonfatal myocardial infarction in the combination 5 + 25 mg group, 2 of 848 (0.2%) with a nonfatal stroke in the combination 5 + 50 mg group, and no events in the other groups. This CV safety analysis of the combination of mirabegron and solifenacin showed rates of CV events comparable with those for monotherapy treatments based on assessments of vital signs, electrocardiograms, and adjudicated CV events.

Patient-reported outcomes from SYNERGY, a randomized, double-blind, multicenter study evaluating combinations of mirabegron and solifenacin compared with monotherapy and placebo in OAB patients

AIMS

To evaluate patient-reported outcomes (PROs) of combinations of solifenacin and mirabegron compared with solifenacin and mirabegron monotherapy and with placebo in patients with overactive bladder (OAB) from the SYNERGY trial.

METHODS

Following a 4-week placebo run-in, period patients (≥18 years) with OAB were randomized 2:2:1:1:1:1 to receive solifenacin 5 mg + mirabegron 25 mg (combination 5 + 25 mg), solifenacin 5 mg + mirabegron 50 mg, (combination 5 + 50 mg), solifenacin 5 mg, mirabegron 25 mg, mirabegron 50 mg or placebo for 12 weeks, followed by a 2-week washout period. At each visit, PROs related to quality of life, symptom bother, and treatment satisfaction were assessed, including OAB-q Symptom Bother score, health-related quality of life (HRQOL) Total score, treatment satisfaction-visual analogue scale (TS-VAS), and patient perception of bladder condition (PPBC) questionnaires.

RESULTS

Overall, 3527 patients were randomized into the study, with 3494 receiving double-blind treatment. At end of treatment (EoT), both combination groups showed greater improvements in OAB-q Symptom Bother score compared with the monotherapy groups (nominal P < 0.001). Statistically significant improvements in HRQOL Total scores were observed in the combination groups versus monotherapy groups (P ≤ 0.002). For both combination groups, the OAB-q Symptom Bother score responder rates at EoT were statistically significantly higher versus mirabegron monotherapy (P < 0.05). The mean adjusted changes from baseline to EoT for PPBC were greater in the combination groups compared with monotherapy groups.

CONCLUSIONS

PROs showed that combination therapy provided clear improvements and an additive effect for many HRQOL parameters, including OAB-q Symptom Bother score, HRQOL Total score, and PPBC.

Impaired contrast sensitivity is associated with more severe cognitive impairment in Parkinson disease

OBJECTIVES

Dopaminergic degeneration affects both nigrostriatal projection neurons and retinal amacrine cells in Parkinson disease (PD). Parkinsonian retinopathy is associated with impaired color discrimination and contrast sensitivity. Some prior studies described associations between color discrimination deficits and cognitive deficits in PD, suggesting that contrast discrimination deficits are due, at least in part, to cognitive deficits in PD. We investigated the relationship between cognitive deficits and impaired contrast sensitivity in PD.

METHODS

PD subjects, n = 43; 15F/28M; mean age 66.5 ± 8.2, Hoehn and Yahr stage 2.6 ± 0.6, and duration of disease of 6.2 ± 5.0 years underwent neuropsychological and Rabin contrast sensitivity testing.

RESULTS

Mean Rabin contrast sensitivity score was 1.34 ± 0.40. Bivariate analyses showed significant correlation between Rabin contrast sensitivity scores and global cognitive z-scores (R = 0.54, P = 0.0002). Cognitive domain Z-score post hoc analysis demonstrated most robust correlation between Rabin scores and executive functions (R = 0.49, P = 0.0009), followed by verbal learning (R = 0.44, P = 0.0028), visuospatial (R = 0.39, P = 0.001) and attention z-scores (R = 0.32, P = 0.036).

CONCLUSIONS

Impaired contrast sensitivity in PD is robustly associated with cognitive deficits, particularly executive function deficits. These results suggest that contrast sensitivity may be a useful biomarker for cognitive changes in PD and may have implications for driving safety evaluations in PD.

Patient and physician preferences for oral pharmacotherapy for overactive bladder: two discrete choice experiments

OBJECTIVE

We examined patient and treating physician (general practitioners, urologists, and [uro]gynecologists) preferences for oral pharmacotherapy (antimuscarinics and beta-3 adrenoceptor agonists) for overactive bladder to gain a deeper understanding of which attributes drive their treatment decision-making and to quantify to what extent.

RESEARCH DESIGN AND METHODS

Two separate discrete choice experiments were developed and validated using the input of patients and physicians. The patient experiment contained the following attributes: micturition frequency, incontinence, nocturia, urgency, dry mouth, constipation, increased heart rate, and increased blood pressure. The physician experiment contained two additional attributes: coping and atrial fibrillation. Both were fielded in five European countries. To allow for preference heterogeneity, utility functions were estimated using a mixed multinomial logit model.

RESULTS

A total of 442 patient and 318 physician responses were analyzed. Patients ranked the attributes based on their largest potential impact on treatment value as follows: incontinence, nocturia, risk of an increased heart rate, urgency, frequency, risk of increased blood pressure, risk of constipation, and risk of dry mouth; and physicians as follows: incontinence, urgency, nocturia, frequency, risk of dry mouth, coping, risk of increased heart rate, risk of increased blood pressure, risk of atrial fibrillation, and risk of constipation. CONCLUSION AND LIMITATIONS: In their valuations, physicians put more emphasis on increasing benefits, whereas patients put more emphasis on limiting risks of side effects. Another contrast that emerged was that patients' valuations of side effects were found to be fairly insensitive to the presented risk levels (with the exception of risk of dry mouth), whereas physicians' evaluated all side effects in a risk-level dependent manner. The obtained utility functions can be used to predict whether, to what extent, and for which reasons patients and physicians would choose one oral pharmacotherapy over another, as well as to advance shared decision-making.

A quantitative benefit-risk assessment approach to improve decision making in drug development: Application of a multicriteria decision analysis model in the development of combination therapy for overactive bladder

A multicriteria decision analysis (MCDA) approach was developed and used to estimate the benefit-risk of solifenacin and mirabegron and their combination in the treatment of overactive bladder (OAB). The objectives were 1) to develop an MCDA tool to compare drug effects in OAB quantitatively, 2) to establish transparency in the evaluation of the benefit-risk profile of various dose combinations, and 3) to quantify the added value of combination use compared to monotherapies. The MCDA model was developed using efficacy, safety, and tolerability attributes and the results of a phase II factorial design combination study were evaluated. Combinations of solifenacin 5 mg and mirabegron 25 mg and mirabegron 50 (5+25 and 5+50) scored the highest clinical utility and supported combination therapy development of solifenacin and mirabegron for phase III clinical development at these dose regimens. This case study underlines the benefit of using a quantitative approach in clinical drug development programs.

Electronic bladder diaries of differing duration versus a paper diary for data collection in overactive bladder

AIMS

This observational study compared data values, reliability, consistency and compliance collected by electronic and paper diaries of differing durations.

METHODS

Subjects ≥18 years with overactive bladder (OAB) on stable antimuscarinic treatment for ≥12 weeks were assigned to one of five, 15-week diary schedules in this randomized, parallel-group observational study. Sample size was sufficient to assess reliability and consistency of diary data with adequate precision. Reliability was assessed via intraclass correlation coefficients, variability with ANCOVAs, and consistency using Cronbach's alpha.

RESULTS

Demographic characteristics of randomized subjects were representative of OAB trial populations. For mean volume voided, reliability was comparable across diary groups. For incontinence, reliability improved with increasing diary duration. For micturition frequency, electronic 7-day diary results had highest reliability and lowest variability. Lowest overall reliability was observed in the 3-day paper diary. Consistency was highest in the electronic continuous groups; Cont A (daily measurements throughout the study period [fully Continuous]) and Cont B (daily measurements for some but not all endpoints of interest [Partially Continuous]). Compliance was generally high; across groups ≥90% of diaries had at least one entry per day. There was no significant change in average micturition frequency with diary duration, suggesting no diary fatigue. One-third of subjects in the electronic Cont B group also reported micturitions as incontinence when they only needed to report incontinence; they also reported lowest satisfaction with the study. The electronic 7-day and electronic Cont A schedules (who reported incontinence and micturitions throughout the study) had lowest residual errors.

CONCLUSIONS

For future OAB trials, 7-day or continuous electronic diaries may improve accuracy and reliability of micturition and incontinence frequency data compared with shorter collection periods and paper diaries. Neurourol. Urodynam. 35:743-749, 2016. © 2015 Wiley Periodicals, Inc.

A phase II dose-ranging study of mirabegron in patients with overactive bladder

Introduction and hypothesis

Mirabegron is a potent and selective β₃-adrenoceptor agonist that may represent an alternative treatment option in place of antimuscarinics for patients with overactive bladder.

Methods

Patients completed a single-blinded, 2-week placebo run-in period followed by 12 weeks of randomized (n = 928) double-blinded treatment with mirabegron oral controlled absorption system (OCAS) 25, 50, 100, or 200 mg once-daily (QD), placebo or tolterodine extended release (ER) 4 mg QD. The primary endpoint was change from baseline to end-of-treatment in mean number of micturition episodes/24 h. Secondary endpoints included changes in mean volume voided per micturition; mean number of urinary incontinence, urgency urinary incontinence, and urgency episodes/24 h; severity of urgency; nocturia; and quality of life measures. Safety parameters included vital signs, adverse events, laboratory tests, electrocardiogram measurements and post-void residual volume.

Results

Mirabegron 25, 50, 100, and 200 mg resulted in dose-dependent reductions (improvements) from baseline to end-of-treatment in micturition frequency of 1.9, 2.1, 2.1, and 2.2 micturitions/24 h respectively, versus 1.4 micturitions/24 h with placebo (p ≤ 0.05 for the mirabegron 50-, 100-, and 200-mg comparisons). There was a statistically significant improvement with mirabegron compared with placebo for most secondary endpoints including quality of life variables. While there was a significant (p < 0.05) increase from baseline in pulse rate in the mirabegron 100-mg and 200-mg groups, this was not associated with an increased incidence of cardiovascular adverse events.

Conclusions

The favorable efficacy and tolerability of mirabegron in this phase II dose-finding study has led to its successful advancement into a phase III clinical development program.

A proof-of-concept study: mirabegron, a new therapy for overactive bladder

AIMS

To evaluate the potential of mirabegron, a selective β3-adrenoceptor agonist, for treatment of overactive bladder (OAB) symptoms.

METHODS

A multicenter, randomized, double-blind, double-dummy, parallel group, placebo and active-controlled, Phase 2, proof-of-concept study was conducted. Eligible patients (n = 314) were enrolled into a single-blind, 2-week placebo run-in period followed by a randomized, double-blind, placebo-controlled treatment period. Patients received mirabegron 100 or 150 mg twice-daily (BID), placebo or tolterodine 4 mg extended release (ER) once-daily for 4 weeks. Primary endpoint was change from baseline to end-of-treatment in mean number of micturition episodes per 24 hr. Secondary endpoints included changes in mean volume voided per micturition; mean number of urinary incontinence, urgency urinary incontinence, and urgency episodes per 24 hr; severity of urgency; nocturia, and quality of life measures. Safety parameters included adverse events, laboratory tests, electrocardiogram parameters and post-void residual volume.

RESULTS

Mirabegron 100 and 150 mg BID resulted in a statistically significant improvement versus placebo in mean change from baseline to end-of-treatment in the primary endpoint of micturition frequency (2.2 micturitions/24 hr vs. 1.2 micturitions/24 hr for both doses, adjusted P ≤ 0.01 for both comparisons). Mirabegron had a statistically significant effect versus placebo for most secondary endpoints, including quality of life variables. Despite a small increase in pulse rate, mirabegron demonstrated good safety and tolerability.

CONCLUSIONS

Mirabegron was efficacious and well tolerated in patients with OAB symptoms and heralds the first of a new class of oral pharmacological therapy for OAB for more than 30 years.

Efficacy of occupant-collected dust samples in the evaluation of residential allergen and fungal levels

This study evaluated the ability of a resident to evaluate their home for allergens and mold using a settled dust test kit compared with evaluation and collection of settled dust by an industrial hygienist. Forty-three home residents were provided with a kit containing written instructions and a vacuum cleaner attachment for collecting a settled dust sample. Within 2 weeks of receiving the occupant-collected sample, an industrial hygienist evaluated these homes, including a visual inspection, collection of settled dust, and collection of spore trap samples. Settled dust samples were analyzed for major dog, cat, dust mite, and cockroach allergens using immunoassay methods, and for mold spore equivalents using quantitative polymerase chain reaction methods for the 13 mold species or species groups comprising the American Relative Moldiness Index (ARMI). Allergen concentrations and ARMIs were compared between the resident- and industrial hygienist-collected samples. Linear regression between the two sets of samples showed strong correlations for dog allergen (r(2) = 0.92) and cat allergen (r(2) = 0.90). Correlations for dust mite (r(2) = 0.57) and cockroach allergens (r(2) = 0.22) were lower, likely due to most samples being near the limit of detection. ARMIs were highly correlated (r(2) = 0.68) and were in categorical (high, medium, or low) agreement for 76% of residences. These results show that residents can reliably follow directions and collect settled dust samples, providing an efficient method to remotely screen homes for elevated allergen levels and to identify homes with a potential mold or moisture problem that may need further evaluation.

Reductions in overactive bladder-related incontinence from pooled analysis of phase III trials evaluating treatment with solifenacin

The embarrassment and social stigma associated with urinary incontinence (UI) in overactive bladder syndrome (OAB) sufferers is a major reason for individuals to seek help for their condition. An analysis of 1,873 subjects with OAB with UI was conducted to assess the efficacy of solifenacin in reducing incontinence in a pooled population from four phase III clinical trials, stratified by severity of incontinence, urgency, and other key factors at baseline. Subjects were randomized to either 5 or 10 mg of solifenacin once daily or placebo for 12 weeks. More than 50% of the total population became continent at study end, with either dose of solifenacin (P<0.01 vs placebo). Significant reductions in incontinence episodes and higher rates of attainment of continence vs placebo were observed irrespective of age or severity of incontinence or urgency at baseline with solifenacin treatment. Treatment was well tolerated, with the majority of adverse events being mild in nature. Solifenacin is an effective antimuscarinic agent for the treatment of incontinence associated with OAB.

Randomized, double-blind placebo- and tolterodine-controlled trial of the once-daily antimuscarinic agent solifenacin in patients with symptomatic overactive bladder

OBJECTIVE

To assess in a phase 3a trial the efficacy of solifenacin succinate, a once-daily oral antimuscarinic agent in development at 5-mg and 10-mg dosage strengths, for the treatment of overactive bladder (OAB) (Yamanouchi Pharmaceutical Co. Ltd, Tokyo, Japan) compared with placebo in patients with symptoms of OAB, i.e. urgency, incontinence, and frequency, with additional objectives being to assess the safety and tolerability of solifenacin and to compare the efficacy and safety of solifenacin with tolterodine 2 mg twice daily.

PATIENTS AND METHODS

The study was an international, multicentre, randomized, double-blind, tolterodine- and placebo-controlled trial conducted at 98 centres. Adult patients with symptomatic OAB for > or = 3 months were eligible; after a single-blind 2-week placebo run-in period patients were randomized equally to a 12-week double-blind treatment with either tolterodine 2 mg twice daily, placebo, solifenacin 5 mg or 10 mg once daily. Efficacy variables included change from baseline in the mean number of urgency, incontinence and urge incontinence episodes, and change from baseline in voids/24 h and mean volume voided/void.

RESULTS

In all, 1281 patients were enrolled, 1081 randomized and 1077 treated; 1033 were evaluated for efficacy. Compared with placebo, the change from baseline (-1.41, -32.7%) in the mean number of urgency episodes per 24 h was statistically significantly lower with solifenacin 5 mg (-2.85, -51.9%) and 10 mg (-3.07, -54.7%; both P < 0.001), but not with tolterodine (-2.05, -37.9%; P = 0.0511). There was a statistically insignificant decrease in episodes of incontinence with tolterodine (-1.14; P = 0.1122) but a significant decrease in patients treated with solifenacin 5 (-1.42; P = 0.008) and 10 mg (-1.45; P = 0.0038). Compared with placebo (-1.20, -8.1%) the mean number of voids/24 h was significantly lower in patients receiving tolterodine (-1.88, -15%; P = 0.0145), solifenacin 5 (-2.19, -17%) and 10 mg (-2.61, -20%; both P < 0.001). The mean volume voided/void was also significantly higher with all three active treatments (P < 0.001). Solifenacin was well tolerated; compared with placebo (4.9%), dry mouth (the most common side-effect), mostly mild, was reported in 18.6% of patients receiving tolterodine, 14.0% receiving 5 mg and 21.3% receiving 10 mg solifenacin.

CONCLUSION

Solifenacin 5 and 10 mg once daily improved urgency and other symptoms of OAB, and was associated with an acceptable level of anticholinergic side-effects. Solifenacin demonstrated significantly favourable efficacy to side-effect ratio in treating symptomatic OAB.

Influence of mutations of Val226 on the catalytic rate of haloalkane dehalogenase

Haloalkane dehalogenase converts haloalkanes to their corresponding alcohols. The 3D structure, reaction mechanism and kinetic mechanism have been studied. The steady state k(cat) with 1,2-dichloroethane and 1,2-dibromoethane is limited mainly by the rate of release of the halide ion from the buried active-site cavity. During catalysis, the halogen that is cleaved off (Cl alpha) from 1,2-dichloroethane interacts with Trp125 and the Cl beta interacts with Phe172. Both these residues have van der Waals contacts with Val226. To establish the effect of these interactions on catalysis, and in an attempt to change enzyme activity without directly mutating residues involved in catalysis, we mutated Val226 to Gly, Ala and Leu. The Val226Ala and Val226Leu mutants had a 2.5-fold higher catalytic rate for 1,2-dibromoethane than the wild-type enzyme. A pre-steady state kinetic analysis of the Val226Ala mutant enzyme showed that the increase in k(cat) could be attributed to an increase in the rate of a conformational change that precedes halide release, causing a faster overall rate of halide dissociation. The k(cat) for 1,2-dichloroethane conversion was not elevated, although the rate of chloride release was also faster than in the wild-type enzyme. This was caused by a 3-fold decrease in the rate of formation of the alkyl-enzyme intermediate for 1,2-dichloroethane. Val226 seems to contribute to leaving group (Cl alpha or Br alpha) stabilization via Trp125, and can influence halide release and substrate binding via an interaction with Phe172. These studies indicate that wild-type haloalkane dehalogenase is optimized for 1,2-dichloroethane, although 1,2-dibromoethane is a better substrate.