Gender specific pharmacokinetic and pharmacodynamic considerations for antimuscarinic drugs for overactive bladder treatment

Novel pharmacotherapeutic avenues for bladder storage dysfunction in men

INTRODUCTION

Bladder storage dysfunction is associated with low quality of life in men and remains a challenging field in pharmacotherapy because of low persistence followed by patient-perceived lack of efficacy and adverse effects. The persistent desire for the development of novel pharmacotherapy is evident, leading to numerous research efforts based on its pathophysiology.

AREAS COVERED

This review describes the pathophysiology, current pharmacotherapeutic strategies, and emerging novel drugs for male bladder storage dysfunction. The section on emerging pharmacotherapy provides an overview of current research, focusing on high-potential target molecules, particularly those being evaluated in ongoing clinical trials.

EXPERT OPINION

As pharmacotherapies targeting alpha-adrenergic, beta-adrenergic, and muscarinic receptors - the current primary targets for treating male bladder storage dysfunction - have demonstrated insufficient efficacy and side effects, researchers are exploring various alternative molecular targets. Numerous targets have been identified as central to regulating bladder afferent nerve activity, and their pharmacological effects and potential have been evaluated in animal-based experiments. However, there is a limited number of clinical trials for these new pharmacotherapies, and they have not demonstrated clear superiority over current treatments. Further research is needed to develop new effective pharmacotherapies for bladder storage dysfunction in men.

Practical solutions for including sex as a biological variable (SABV) in preclinical neuropsychopharmacological research

Recently, many funding agencies have released guidelines on the importance of considering sex as a biological variable (SABV) as an experimental factor, aiming to address sex differences and avoid possible sex biases to enhance the reproducibility and translational relevance of preclinical research. In neuroscience and pharmacology, the female sex is often omitted from experimental designs, with researchers generalizing male-driven outcomes to both sexes, risking a biased or limited understanding of disease mechanisms and thus potentially ineffective therapeutics. Herein, we describe key methodological aspects that should be considered when sex is factored into in vitro and in vivo experiments and provide practical knowledge for researchers to incorporate SABV into preclinical research. Both age and sex significantly influence biological and behavioral processes due to critical changes at different timepoints of development for males and females and due to hormonal fluctuations across the rodent lifespan. We show that including both sexes does not require larger sample sizes, and even if sex is included as an independent variable in the study design, a moderate increase in sample size is sufficient. Moreover, the importance of tracking hormone levels in both sexes and the differentiation between sex differences and sex-related strategy in behaviors are explained. Finally, the lack of robust data on how biological sex influences the pharmacokinetic (PK), pharmacodynamic (PD), or toxicological effects of various preclinically administered drugs to animals due to the exclusion of female animals is discussed, and methodological strategies to enhance the rigor and translational relevance of preclinical research are proposed.

The Release of 24 h Infravesical Obstruction in Mice: Changes in Molecular, Morphological, and Functional Parameters for 14-Day Observation

Bladder outlet obstruction (BOO) induces bladder dysfunction and altered bladder architecture. Irrespective of the release of the obstruction, persistent bladder dysfunction severely affects the quality of life. A better understanding of the repair process offers an opportunity to enhance postintervention management. We subsequently evaluated the postobstructive repair process in mice subjected to 24 h BOO followed by release. Male and female mice bladders were obstructed for 24 h by placing a clip around the bladder neck. After the release of obstruction, the mice were studied for 3, 7, and 14 days to observe the bladder repair process over time. Voiding frequency and volume were recorded using the voiding spot assay, and the transcutaneous glomerular filtration rate (tGFR) was measured. Fibrogenesis and associated gene expressions and altered protein levels were evaluated in the bladder using histology, quantatative polymerase chain reaction (qPCR), and Western blot analyses. Bladder wall thickness was increased in both genders over time but occurred later in female mice. Moreover, collagen deposition in the smooth muscle layer increased over time in both genders. Male mice showed a decreased average voided volume at 3 days post release, while female mice showed no significant change during the time course. Fibrosis-related molecular events, including upregulation of fibronectin (FN) protein and Collagen-3 (Col-3) mRNA expression, were transient and normalized again at 14 days in both genders. Transforming growth factor-β (TGF-β) and bone morphogenic protein (BMP)-7 mRNA expressions were upregulated at 14 days post release in both genders. Transcutaneous GFR remained normal during the time course. Release of 24 h BOO initiated a bladder remodeling process. The animal model enables a wide range of experiments to study bladder remodeling, and gender differences offer potential targets for understanding bladder fibrosis and adaptation with BOO.

Pharmacokinetics of gallic acid and protocatechuic acid in humans after dosing with Relinqing (RLQ) and the potential for RLQ-perpetrated drug-drug interactions on organic anion transporter (OAT) 1/3

CONTEXT

Relinqing granules (RLQ) are being used alone or in combination with antibacterial drugs to treat urological disorders.

OBJECTIVE

This study investigates the pharmacokinetics of RLQ in humans and the potential for RLQ-perpetrated interactions on transporters.

MATERIALS AND METHODS

Twelve healthy subjects (six women and six men) participated to compare single- and multiple-dose pharmacokinetics of RLQ. In the single-dose study, all 12 subjects received 8 g of RLQ orally. After a 7-d washout period, the subjects received 8 g of RLQ for seven consecutive days (t.i.d.) and then a single dose. Gallic acid (GA) and protocatechuic acid (PCA) in plasma and urine samples were analysed using LC-MS/MS. The transfected cells were used to study the inhibitory effect of GA (50-5000 μg/L) and PCA (10-1000 μg/L) on transporters OAT1, OAT3, OCT2, OATP1B1, P-gp and BCRP.

RESULTS

GA and PCA were absorbed into the blood within 1 h after administration and rapidly eliminated with a half-life of less than 2 h. The mean peak concentrations of GA (102 and 176 μg/L) and PCA (4.54 and 7.58 μg/L) were lower in males than females, respectively. The 24 h urine recovery rates of GA and PCA were about 10% and 5%, respectively. The steady-state was reached in 7 d without accumulation. GA was a potent inhibitor of OAT1 (IC₅₀ = 3.73 μM) and OAT3 (IC₅₀ = 29.41 μM), but not OCT2, OATP1B1, P-gp or BCRP.

DISCUSSION AND CONCLUSIONS

GA and PCA are recommended as PK-markers in RLQ-related pharmacokinetic and drug interaction studies. We should pay more attention to the potential for RLQ-perpetrated interactions on transporters.

Patient Expectations of Assigned Treatments Impact Strength of Randomised Control Trials

Patient engagement with treatments potentially poses problems for interpreting the results and meaning of Randomised Control Trials (RCTs). If patients are assigned to treatments that do, or do not, match their expectations, and this impacts their motivation to engage with that treatment, it will affect the distribution of outcomes. In turn, this will impact the obtained power and error rates of RCTs. Simple Monto Carlo simulations demonstrate that these patient variables affect sample variance, and sample kurtosis. These effects reduce the power of RCTs, and may lead to false negatives, even when the randomisation process works, and equally distributes those with positive and negative views about a treatment to a trial arm.

Low Intensity Extracorporeal Shock Wave Therapy as a Potential Treatment for Overactive Bladder Syndrome

Simple Summary

Overactive bladder (OAB) is a common urologic condition with urinary frequency, urinary urgency, nocturia, and urgency incontinence, which can get in the way of a patient’s social life, exercise, work, and sleep. Exploring a promising option for OAB patients is very important, especially one with less side effects or invasive alternations. This study uses low intensity extracorporeal shock wave therapy (LiESWT) to investigate the therapeutic effect and duration on OAB symptoms.

Abstract

Background: The present study attempted to investigate the therapeutic effect and duration of low intensity extracorporeal shock wave therapy (LiESWT) on overactive bladder (OAB) symptoms, including social activity and the quality of life (QoL). Methods: In this prospective, randomized, single-blinded clinical trial, 65 participants with OAB symptom were randomly divided into receive LiESWT (0.25 mJ/mm², 3000 pulses, 3 pulses/second) once a week for 8 weeks, or an identical sham LiESWT treatment without the energy transmission. We analyzed the difference in overactive bladder symptom score (OABSS) and 3-day urinary diary as the primary end. The secondary endpoint consisted of the change in uroflowmetry, post-voided residual (PVR) urine, and validated standardized questionnaires at the baseline (W0), 4-week (W4) and 8-week (W8) of LiESWT, and 1-month (F1), 3-month (F3) and 6-month (F6) follow-up after LiESWT. Results: 8-week LiESWT could significantly decrease urinary frequency, nocturia, urgency, and PVR volume, but meaningfully increase functional bladder capacity, average voided volume and maximal flow rate (Qmax) as compared with the W0 in the LiESWT group. In addition, the scores calculated from questionnaires were meaningfully reduced at W4, W8, F1, F3, and F6 in the LiESWT group. Conclusions: Our results revealed that the therapeutic efficacy of LiESWT could improve voided volume and ameliorate OAB symptoms, such as urgency, frequency, nocturia, and urinary incontinence, and lasted up to 6 month of follow-up. Moreover, LiESWT treatment brought statistically significant and clinically meaningful improvements in social activity and QoL of patients. These findings suggested that LiESWT could serve as an alternative non-invasive therapy for OAB patients.