Intravesical oxybutynin therapy for patients with neurogenic detrusor overactivity: a systematic review and meta-analysis

Short‑term effects of oxybutynin dosage in individuals with neurogenic bladder following spinal cord injury: A retrospective cohort study

The aim of the present study was to determine the relationship between dose of oxybutynin and reduction in detrusor pressure in individuals with neurogenic bladder (NGB) secondary to spinal cord injury (SCI). The hospital-based data were examined for all individuals with NGB and SCI who were admitted for urological evaluation between January 1999 and December 2016. Patient characteristics, urodynamics and bladder management details were collected at pre-treatment and post-treatment. The primary outcome used to assess oxybutynin treatment was the change in detrusor pressure (Pdet). Analysis of covariance (ANCOVA) was used to investigate the relationship between dosage of oxybutynin and decrease in Pdet. A total of 245 participants (112 who received no medication and 133 treated with oxybutynin) were included. After controlling for confounding factors, each 1 mg increase in oxybutynin was associated with a mean decrease of 0.9 cmH2O in Pdet (95% CI, -1.4 to -0.3). Stratifying bladder management by indwelling catheter, oxybutynin at a dose of 1 mg was associated with a mean decrease in Pdet of 0.5 cmH2O (95% CI, -1.4 to 0.4) in patients with indwelling catheters and 1.0 cmH2O (95% CI, -1.7 to -0.3) in patients with clean intermittent catheterization and balanced bladder. This study provided guidance for setting the starting dose of drugs associated with response variability in NGB with SCI. Oxybutynin is deemed to be clinically effective for managing NGB in patients with SCI.

[Intravesical oxybutynin treatment for neurogenic detrusor overactivity : Efficacy and safety data from clinical practice with the first intravesical oxybutynin treatment authorized in Germany]

Existing therapies for neurogenic detrusor overactivity (NDO), i.e. oral anticholinergics and botulinum toxin injections, can be associated with serious adverse effects or are not always sufficiently effective. Therefore, there is a need for alternative safe and effective treatment options for NDO. Intravesical oxybutynin has been successfully used for several years as a prescription drug in adults and children with spinal cord injury and spina bifida. In 2019, VESOXX® (FARCO-PHARMA, Cologne, Germany) became the first registered intravesical oxybutynin product in Germany, which is indicated for the suppression of neurogenic detrusor overactivity (NDO) in children from 6 years of age and adults, who are managing bladder emptying by clean intermittent catheterisation (CIC), if they cannot be adequately managed by oral anticholinergic treatment due to lack of efficacy and/or intolerable side effects. Overall, there are limited data regarding therapy with intravesical oxybutynin, with the majority of publications being retrospective case series. To date, there are limited data on the efficacy and safety of the newly approved intravesical oxybutynin therapy (VESOXX®) in NDO patients. This noninterventional case series from daily routine treatment which evaluated the physician reports of 38 patients suggests that intravesical oxybutynin effectively improves maximum detrusor pressure (Pdet max) by decreasing it by 59% from 51.94 cm H2O ± 26.12 standard deviation (SD) to 21.07 cm H2O ± 17.32 SD (P < 0.001, n = 34). Maximum bladder pressure (MBC) increased by 34% from 260.45 ml ± 200.26 SD to 348.45 ml ± 175.90 SD. Positive or similar effects compared to previous therapies were seen in bladder morphology, number of incontinence episodes, urinary tract infections and adverse drug effects. This case series demonstrates that intravesical oxybutynin is an important addition to current therapies for the treatment of NDO and it is also efficacious in the rare setting of other underlying diseases beyond spinal cord injury or spina bifida. The approved intravesical oxybutynin preparation VESOXX® may be a useful alternative for patients who do not respond to other therapies or suffered side effects.

Treatment modalities for paediatric functional daytime lower urinary tract disorders: an updated review

Paediatric functional bladder disorders especially those causing daytime symptoms are a common cause of significant psychosocial and/or physical morbidity and impaired quality of life. Despite the availability of many therapeutic modalities, a significant number of children appear to be refractory to treatment and continue to have symptoms. In this review, we aim to evaluate the current evidence in the use of existing and novel therapeutic options for the management of daytime lower urinary tract disorders in children. We also aim to highlight the controversies around the terminology and diagnosis of paediatric lower urinary tract dysfunction (LUTD) and specific conditions. The article will then provide a reasonable critique of the existing and emerging treatment modalities in functional daytime LUTD in children including their mode of action, efficacy, indications, and recent advances. These include standard urotherapy, specific urotherapy comprised of biofeedback, alarm therapy and electrical neural stimulation and pharmacotherapy involving selective and non-selective anticholinergics, ß3 adrenergic agonists, alpha blockers and botulinum toxin. A better understanding of this common clinical problem may help clinicians achieve better profiling of these children's diagnoses to further enable specific, targeted treatment.

Treating Lower Urinary Tract Symptoms in Older Adults: Intravesical Options

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

Daidzein is the in vivo active compound of Puerariae Lobatae Radix water extract for muscarinic receptor-3 inhibition against overactive bladder

Background: In the previous study, Puerariae Lobatae Radix (named Gegen in Chinese) water extract attenuated M3 receptor agonist carbachol-induced detrusor contraction after 3-week oral administration in a hypertension-associated OAB (overactive bladder) model. This research aimed to investigate the active ingredients from Gegen water extract against OAB.

Methods: Bioassay-guided fractionation was performed by using preparative HPLC for fast isolation of fractions followed by screening their ex vivo activity through carbachol-induced bladder strip contraction assay. Chemicals in each active fraction were analyzed by HPLC-UV. Urine metabolites were quantified by LC-MS/MS after sub-acute administration. Thermal shift assay with the recombinant human M3 receptor protein was performed, and molecular docking analysis was used for molecular modelling of M3 receptor inhibition.

Results: Bioassay-guided fractionation results for isolating M3 receptor inhibitors indicated that four compounds were identified as active ingredients of Gegen water extract, and their inhibition potency on carbachol-induced detrusor contraction was ranked in descending order according to their inhibition concentrations as follows: genistein > daidzein > biochanin A >> puerarin. Daidzein in urine reached an ex vivo effective concentration to inhibit detrusor contraction, but others did not. Daidzein concentration-dependently increased the melt temperature (Tm) of recombinant human M3 receptor protein with a positive binding (ΔTm = 2.12 °C at 100 μg/ml). Molecular docking analysis showed that daidzein can potently bind to the ligand binding pocket of the M3 receptor via hydrogen bonding.

Conclusion: Puerarin and its derivatives were pro-drugs, and daidzein was their in vivo active form via M3 receptor inhibition for treating OAB.