Discontinuation rates and inter-injection interval for repeated intravesical botulinum toxin type A injections for detrusor overactivity

Factors Associated With Onabotulinum Toxin-A Discontinuation in a Diverse Urban Population

IMPORTANCE

Although overactive bladder (OAB) is a common condition, affecting 16% of Americans, few patients continue on to advanced therapies. Furthermore, procedural therapies like intravesical onabotulinum toxin-A (BTX-A), which require ongoing repeat treatments, have discontinuation rates ranging from 25% to 51%.

OBJECTIVES

This study sought to investigate factors associated with dis-continuation of BTX-A injections for idiopathic OAB among a diverse urban population.

STUDY DESIGN

This was a retrospective review of adults 18 years and older who underwent BTX-A injection for idiopathic OAB. Patient demographics, past medical history, symptoms, and postprocedural outcomes such as subjective improvement, urinary retention, and incidence of urinary tract infection were compared between groups.

RESULTS

Onabotulinum toxin-A injections were administered to 246 patients who met study criteria, of whom 211 (85.7%) were women. One hundred (40.7%) patients discontinued BTX-A therapy. Patients discontinuing BTX-A therapy were more likely to have developed postprocedural urinary retention (18.4% vs 9.7%, P < 0.05) and had a higher median income by zip code ($59,000 vs $50,000; P < 0.01). Patients were significantly more likely to continue BTX-A therapy if they reported preprocedural nocturia (57.2% vs 36.8%, P < 0.01) or urgency urinary incontinence (UUI) (78.1% vs 64.6%, P < 0.05).

CONCLUSIONS

Adverse outcomes, such as postprocedural urinary retention, are associated with discontinuation of BTX-A therapy. Patients who reported nocturia and UUI before injection were more likely to continue BTX-A suggesting more severe OAB is more responsive to this therapy. Given the large proportion (>40%) of patients who discontinued BTX-A treatment, further research is needed to identify barriers to continuation of care.

Real-world onabotulinumtoxinA treatment patterns in patients with overactive bladder

PURPOSE

Utilization patterns of third-line onabotulinumtoxinA for overactive bladder (OAB) symptoms-including discontinuation and use of other therapeutic options during or after treatment-are not well understood. This retrospective analysis of administrative claims was designed to characterize the unmet need for OAB treatment.

MATERIALS AND METHODS

A retrospective claims analysis of Optum's deidentified Clinformatics® Data Mart Database (2009-2021) was performed among patients with diagnosis of OAB newly starting onabotulinumtoxinA injection (2015-2017). Study measures were evaluated during an 18-month pretreatment baseline and over a minimum of 36 months of follow-up. These included number of injections, days between injections, other measures of onabotulinumtoxinA utilization, use of second-line pharmacologic treatments, use of device and surgical treatment options, and complications.

RESULTS

Of 2505 eligible patients, 535 (21.4%; 66.8 ± 13.3 y, 87.3% females) continued onabotulinumtoxinA throughout the study. The remaining 1970 (78.6%; 71.4 ± 11.6 y, 79.1% females) were considered discontinuers. Of continuers, 57% received ≥5 treatments. Of discontinuers, 84% received ≤2 treatments. Anticholinergics and β3-adrenoceptor agonist medication use declined in all patients from baseline to follow-up; however, the absolute reduction in the proportion with any medication fill was similar across continuers versus discontinuers (21% vs. 18%, p < 0.0001). Sacral neuromodulation was initiated by 15/535 (3%) of continuers and 137/1970 (7%) of discontinuers (p < 0.0001). No patients initiated percutaneous tibial neuromodulation.

CONCLUSIONS

Early discontinuation of onabotulinumtoxinA therapy for OAB is common and most discontinuers do not receive alternative treatments. Providers have the opportunity to educate OAB patients with un- or undertreated symptoms regarding alternative options.

OnabotulinumtoxinA discontinuation in patients with prior nerve stimulation

PURPOSE

The objective of this study is to describe the characteristics of patients who discontinue onabotulinumtoxinA treatment for overactive bladder (OAB) and to determine the impact of prior sacroneuromodulation or peripheral nerve stimulation on the discontinuation rates of onabotulinumtoxinA.

MATERIALS AND METHODS

This is a retrospective cohort study of women with at least two onabotulinumtoxinA (BTX-A) treatments for OAB with a Female Pelvic Medicine and Reconstructive surgeon at a referral center between January 2014 and July 2019. Patients were excluded if they underwent BTX-A treatment in the operating room or utilized clean intermittent catheterization at baseline. Women who continued injections throughout the study period were compared to those who did not. Discontinuation was defined as stopping BTX-A during the study period. Treatment failure was defined as a documented failure in the chart and/or moving to other OAB treatments. Loss to follow-up was defined as no follow-up greater than 12 months after the last injection. Discontinuation-free and failure-free survival were estimated by Kaplan-Meier analysis.

RESULTS

A total of 214 women met the inclusion criteria with a mean age of 62.9 ± 14 years. Fifty percent were Black. Eighty-six (40.2%) discontinued onabotulinumtoxinA treatment during the study period. There were no demographic differences between patients who discontinued BTX-A and those who continued with the following exceptions: patients who discontinued had higher rates of prior pelvic reconstructive surgery (19.8% vs. 10.2%, p = 0.04) and were more likely to have the concurrent diagnosis of painful bladder syndrome (9.3% vs. 2.3%, p = 0.03). Patients diagnosed with a urinary tract infection (UTI) after ≥50% of treatments were more likely to discontinue (27.9% vs. 14.1%, p = 0.01). On multivariate logistic regression analysis, patients with recurrent UTIs after treatment were significantly more likely to discontinue than those who do not (odds ratio: 2.61, [1.17, 5.82]). Of the cohort, 54 (25%) patients had previously undergone nerve stimulation. A total of 27.8% of patients with prior nerve stimulation discontinued BTX-A compared to 44.4% of those without prior third line treatment (p = 0.03). Patients with prior nerve stimulation had a higher discontinuation-free survival rate (p = 0.013) but there was no difference in failure-free survival.

CONCLUSIONS

Patients who have recurrent UTIs after onabotulinumtoxinA injections are 2.6 times more likely to discontinue treatment than those who do not have infections. Patients with prior exposure to nerve stimulation have a significantly lower onabotulinumtoxinA discontinuation rate, but there is no difference in failure rates.

Clinical Application of Botulinum Neurotoxin in Lower-Urinary-Tract Diseases and Dysfunctions: Where Are We Now and What More Can We Do?

Botulinum toxin A (Botox) had been considered a promising drug that has an effect on functional disorders of the lower urinary tract. Because Botox exhibits anti-inflammatory and antispasmodic effects, Botox injection into the bladder can decrease detrusor contractility, reduce bladder hypersensitivity, and eliminate painful sensations. Injecting Botox into the bladder outlet can relax the hyperactivity of the bladder neck, and of the urethral smooth and striated muscles. Based on these therapeutic effects, Botox has been widely applied to treat lower-urinary-tract dysfunctions (LUTDs) such as overactive bladder and neurogenic detrusor overactivity. However, this treatment has not been licensed for use in other LUTDs such as interstitial cystitis, voiding dysfunction due to benign prostatic hyperplasia in men, and dysfunctional voiding in women. Botox has also not been approved for the treatment of children with overactive bladder and dysfunctional voiding; in patients with spinal cord injuries with detrusor sphincter dyssynergia and autonomic dysreflexia; or for poorly relaxed external sphincter in non-neurogenic patients. This article reviews the current knowledge regarding Botox treatment for LUTDs and discusses the potential clinical applications of Botox, as well as work that can be conducted in the future.

IncobotulinumtoxinA versus OnabotulinumtoxinA intradetrusor injections in patients with neurogenic detrusor overactivity incontinence: a double-blind, randomized, non-inferiority trial

BACKGROUND

A randomized, double-blind, non-inferiority clinical study was performed on the efficacy and tolerability of IncobotulinumtoxinA vs OnabotulinumtoxinA intradetrusor injections in patients with refractory neurogenic detrusor overactivity incontinence performing intermittent catheterization.

METHODS

Sixty-four patients with Spinal Cord Injury or Multiple Sclerosis were randomized to receive 30 intradetrusor injections of IncobotulinumtoxinA or OnabotulinumtoxinA 200 U; 28 patients in IncobotulinumtoxinA group and 29 in OnabotulinumtoxinA group completed the study. Primary outcome measure was the noninferior variation from baseline in daily urinary incontinence episodes (week 12), with a non-inferiority margin of one episode/day. Secondary outcomes measures were changes in Incontinence- Quality of Life questionnaire, Visual Analog Scale score (bother of symptoms on Quality of Life), urodynamic parameters, occurrence of adverse effects and related costs (week 12).

RESULTS

At week 12, mean value of difference in urinary incontinence episodes/day between the two groups was -0.2 (95% two-sided CI: -1; 0.7); the difference in incontinence episodes/day between the two groups was -0.4 with a higher limit of one-sided 95% CI of 0.2 episodes/day which was much lower than the non-inferiority margin of one episode/day. Total score and subscores of Incontinence- Quality of Life questionnaire, Visual Analog Scale Scores and urodynamics did not show differences between the two groups. Adverse effects were similar for both treatments, with urinary tract infection being the most frequent, localised effect. Minor costs were observed following IncobotulinumtoxinA.

CONCLUSIONS

In patients with refractory neurogenic incontinence due to Spinal Cord Injury or Multiple Sclerosis, IncobotulinumtoxinA was not inferior to OnabotulinumtoxinA in improving clinical and urodynamic findings in the short-term follow-up, with comparable adverse effects but minor costs.

Long-term follow-up reveals a low persistence rate of abobotulinumtoxinA injections for idiopathic overactive bladder

INTRODUCTION

Little is known about long-term efficacy and tolerance of intra-detrusor injections of abobotulinumtoxinA for management of idiopathic overactive bladder (OAB). We report long-term efficacy and compliance of abobotulinumtoxinA in patients treated for OAB.

METHODS

All patients treated with abotulinumtoxinA for OAB in a tertiary reference centre between 2005 and 2012 were included in a retrospective analysis. Patients received 150, 250 or 500 U of abotulinumtoxinA as first injection. The primary endpoint was the discontinuation rate at 5 years. Other outcomes of interest were: rate of failure, reasons for discontinuation and subsequent treatment elected in those who did not persist with abobotulinumtoxinA.

RESULTS

Fifty-nine patients (50 women and 9 men) were included. Forty-one patients (69.4%) received 250 U of abobotulinumtoxinA as first injection. Thirteen patients (22%) received 500 U and 5 (8.4%) received 150 U of BoNT-A. Median follow-up was 83.6 months [0.3-183.6]. Median number of injections per patient was 2 [1-15] and median reinjection interval was 10.7 [3-86.4] months. The estimated 5-year discontinuation-free survival rate was 23.4%. Fourteen patients (23.7%) experienced persistent improvement of symptoms and 12 patients (20.3%) stopped the injections because of tolerability issues. Main cause of discontinuation was primary failure, which occurred in 21 patients (35.5%).

CONCLUSION

Overall, 59.3% of patients were successfully treated with first abobotulinumtoxinA injection. Although the estimated 5-year discontinuation-free survival rate is low, abobotulinumtoxinA could be considered as an alternative off-labelled in patients not responders to onabotulinumtoxinA after failure of other conservative measures.

LEVEL OF PROOF

3.

Long term continuation with repeated Botulinum toxin A injections in people with neurogenic detrusor overactivity after spinal cord injury

STUDY DESIGN

Retrospective chart study.

OBJECTIVES

The aim was to examine continuation of treatment of individuals with spinal cord injury including myelomeningocele and neurogenic detrusor overactivity, treated with repeated intra-detrusor Botulinum toxin A injections, and to investigate factors associated with discontinuation of treatment.

SETTING

Rigshospitalet, Denmark METHODS: This study included 128 individuals with spinal cord injury and neurogenic detrusor overactivity, who were offered repeated Botulinum toxin A injections between 2001 and 2018. Continuation rates of the treatment were estimated using Kaplan Meier analysis. A Cox proportional hazard analysis was used to investigate factors predictive of discontinuation.

RESULTS

A total of 1156 treatments were performed. The median number of treatments was six (IQR 9, range 1-51), and median follow-up was 10.6 years (IQR 8.5, range 0-16.9). All urodynamic parameters changed significantly after the first treatment (p < 0.001). The continuation group had significantly higher mean maximum bladder capacity after the first injections compared with the discontinuation group, with a mean difference between the groups of 84.5 mL (95% CI 4.7-164.2) (p = 0.038). The probability of continuing treatments after 5 years was 59% (95% CI 50.0-67.8) and 50% (95% CI 40.1-59.3) after 10 years. Individuals aged 31-50 years were more likely to continue treatment compared with those aged >50 years (95% CI 0.21‒0.79) (p = 0.008). No other factors predicted discontinuation.

CONCLUSIONS

This long-term follow-up study showed that 50% of people with spinal cord injury starting intra-detrusor Botulinum toxin A for neurogenic detrusor overactivity are still receiving injections after 10 years.

Outcomes of Intradetrusor Onabotulinum Toxin A Therapy in Overactive Bladder Refractory to Sacral Neuromodulation

Purpose

Intradetrusor onabotulinum toxin A (BTXA) and sacral neuromodulation (SNM) are effective third-line therapies for overactive bladder (OAB). We aimed to measure the outcomes of BTXA for treatment of OAB refractory to initial SNM and identify patient characteristics associated with these outcomes.

Methods

This retrospective cohort study included patients who failed to respond to initial SNM treatment for OAB and subsequently received BTXA at a single provider’s clinic between January 2013 and December 2016. Treatment successes were defined as patients willing to continue BTXA or who found symptom relief whereas treatment failures discontinued BTXA due to adverse effects or lack of symptom relief. Symptoms and patient-reported outcomes on validated questionnaires were compared before the initial BTXA trial to 2 months after the last BTXA treatment. The SNM failure BTXA groups were also compared to BTXA SNM naïve groups.

Results

Of 18 patients who received BTXA after failed SNM treatment, 7 (39%) achieved treatment success. Successfully treated patients demonstrated decreased urinary frequency from a median 11 voids/day pre-BTXA to 8 voids/day with BTXA (P=0.042). Patients whose treatment failed reported increased complaints of a weak urinary stream (P=0.03) and higher frequency of straining to urinate (P=0.016) than the successful treatment group pre-BTXA. Compared to BTXA patients without prior SNM, the odds of failing BTXA after initial SNM were 3.6 times higher (P=0.016).

Conclusions

BTXA appears effective for OAB refractory to SNM, although the success rate is lower compared to BTXA patients without SNM exposure.

The Management of Lower Urinary Tract Dysfunction in Multiple Sclerosis

PURPOSE OF REVIEW

Multiple sclerosis (MS) is the most frequent neuroinflammatory disease of the central nervous system and is commonly associated with lower urinary tract (LUT) dysfunction. As a consequence, health-related quality of life is often impaired and the upper urinary tract might be at risk for damage. The aim of this review is to give an overview of current treatment options for LUT dysfunction in patients with MS.

RECENT FINDINGS

The treatment is tailored to the type of dysfunction-storage or voiding dysfunction-beginning with conservative treatment options and ending with invasive therapies and surgery. Additionally, alternative options, e.g., different intravesical therapies or cannabinoids, have been evaluated in recent years with promising results. Current available therapies offer different possible treatments for LUT dysfunction in patients with MS. They address either voiding or storage dysfunction and therefore ameliorate LUT symptoms improve quality of life and protect the upper urinary tract.

Management of Idiopathic Overactive Bladder Syndrome: What Is the Optimal Strategy After Failure of Conservative Treatment?

CONTEXT

A considerable number of patients affected by the overactive bladder syndrome (OAB) do not respond to pharmacotherapy and bladder training due to unsatisfactory response or intolerability.

OBJECTIVE

To review the available literature assessing therapeutic effect of the available third-line treatment modalities for OAB.

EVIDENCE ACQUISITION

PubMed, Medline, and Cochrane databases were searched for all studies comparing outcomes of the available third-line treatment modalities for OAB.

EVIDENCE SYNTHESIS

Several minimally invasive surgical procedures are available for patients with refractory OAB. These therapies include intravesical botulinum toxin type A, posterior tibial nerve stimulation, and sacral neuromodulation.

CONCLUSIONS

None of the mentioned therapeutic modalities shows strong superiority over another. If the results of one therapy are not satisfactory, switching to another third-line treatment can be attempted. The treatment algorithm is dependent on several factors, including age, comorbidity, patient preference, surgical expertise, and financial concerns. All these factors should be taken into consideration before initiation of treatment.

PATIENT SUMMARY

In the management of drug-resistant overactive bladder syndrome, the different minimally invasive treatments that are available are equal. If the results of one therapy are not satisfactory, switching to another treatment can be attempted. The treatment algorithm is dependent on several factors, including age, comorbidity, patient preference, surgical expertise, and financial concerns.

Two-Year Outcomes of Sacral Neuromodulation Versus OnabotulinumtoxinA for Refractory Urgency Urinary Incontinence: A Randomized Trial

BACKGROUND

Urgency urinary incontinence (UUI) is a chronic condition for which sacral neuromodulation (SNM) (InterStim/Medtronic) and onabotulinumtoxinA (BTX) (BotoxA/Allergan) are utilized. These therapies have not been compared over extended time.

OBJECTIVE

To compare UUI episodes (UUIE) over 24 mo following SNM or BTX.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, open-label, randomized, extension trial (February 2012-July 2016) at nine US medical centers involving 386 women with ≥6 UUIE over 3 d inadequately managed by medications. Participants were clinical responders to treatment: ≥50% reduction in UUIEs after SNM placement or 1 mo post BTX.

INTERVENTION

SNM (n=194) versus 200 U BTX (n=192). SNM reprogrammings occurred throughout the 24 mo. After 6 mo, two additional BTX injections were allowed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Primary outcome: change in mean daily UUIE over 24 mo.

SECONDARY OUTCOMES

no UUIE, ≥75% and ≥50% UUIE reduction; Overactive Bladder Questionnaire Short Form; Urinary Distress Inventory short form; Incontinence Impact Questionnaire; Patient Global Impression of Improvement; Overactive Bladder Satisfaction of Treatment Questionnaire; and adverse events (AEs). Primary analysis used a linear mixed model.

RESULTS AND LIMITATIONS

Outcome data were available for 260/298 (87%) clinical responders. No difference in decreased mean UUIE was found over 24 mo (-3.88 vs -3.50 episodes/d,95% confidence interval [CI]=-0.14-0.89; p=0.15), with no differences in UUI resolution, ≥75% or ≥50% UUIE reduction. BTX group maintained higher satisfaction (mean difference=-9.14, 95% CI=-14.38--3.90; p<0.001), treatment endorsement (mean difference=-12.16, 95% CI=-17.7--6.63; p<0.001) through 24 mo. Other secondary measures did not differ. Recurrent urinary tract infections (UTIs) were higher after BTX (24% vs 10%; p<0.01), 6% required intermittent catheterization post second injection. SNM revision and removals occurred in 3% and 9% patients, respectively.

CONCLUSIONS

Both treatments offered sustainable UUI improvement, and higher BTX dosing had low clean intermittent catheterization rates, but with UTI risk. SNM revision/removal rates were low due to standardized lead placement with strict treatment response definitions.

PATIENT SUMMARY

We compared a large group of US women with severe urgency urinary incontinence (UUI) who received sacral neuromodulation (InterStim) or onabotulinumtoxinA (Botox A) therapy during a 2-yr period. We found that both therapies had similar success in reducing UUI symptoms, and adverse events were low. However, women in the BotoxA group had higher satisfaction and endorsement with their treatment, but with a higher chance of a urinary tract infection. We conclude that both therapies offer sustained reduction in daily incontinence over 2 yr.

Medium- to long-term outcomes of botulinum toxin A for idiopathic overactive bladder

Botulinum toxin A (BoNT-A) has become an important therapeutic tool in the management of refractory overactive bladder (OAB). Over the last decade, there have been growing numbers of patients receiving repeat injections and these outcomes have begun to be reported in large, high-quality cohorts. This article reviews the current evidence for the medium- to long-term use of BoNT-A in adults with idiopathic detrusor overactivity (IDO) receiving repeat injections. We find that medium-term outcomes are encouraging but long-term outcomes are not as extensively reported. There is high-quality evidence that efficacy following the first injection persists across multiple treatment cycles. There are no additional safety concerns from repeat injections up to six treatment cycles. However, there is a need for further data to confirm the efficacy and safety of BoNT-A beyond the follow-up period in the current literature.

OnabotulinumtoxinA in the treatment of overactive bladder: a cost-effectiveness analysis versus best supportive care in England and Wales

The cost-effectiveness of onabotulinumtoxinA (BOTOX(®)) 100 U + best supportive care (BSC) was compared with BSC alone in the management of idiopathic overactive bladder in adult patients who are not adequately managed with anticholinergics. BSC included incontinence pads and, for a proportion of patients, anticholinergics and/or occasional clean intermittent catheterisation. A five-state Markov model was used to estimate total costs and outcomes over a 10-year period. The cohort was based on data from two placebo-controlled trials and a long-term extension study of onabotulinumtoxinA. After discontinuation of initial treatment, a proportion of patients progressed to downstream sacral nerve stimulation (SNS). Cost and resource use was estimated from a National Health Service perspective in England and Wales using relevant reference sources for 2012 or 2013. Results showed that onabotulinumtoxinA was associated with lower costs and greater health benefits than BSC in the base case, with probabilistic sensitivity analysis indicating an 89 % probability that the incremental cost-effectiveness ratio would fall below £20,000. OnabotulinumtoxinA remained dominant over BSC in all but two scenarios tested; it was also economically dominant when compared directly with SNS therapy. In conclusion, onabotulinumtoxinA appears to be a cost-effective treatment for overactive bladder compared with BSC alone.

Long-term follow-up of intravesical botulinum toxin-A injections in women with idiopathic overactive bladder symptoms

INTRODUCTION

Intravesical botulinum toxin (BoNT-A) is a safe and effective treatment for overactive bladder syndrome. There are many reports on the clinical experience with BoNT-A, especially in patients with neurogenic detrusor overactivity. The US Food and Drug Administration has recently approved its use for idiopathic overactive bladder (iOAB). Various studies have reported positive results for iOAB in the short-term. Yet little is known about the results after repeated BoNT-A injections. In this study, we evaluated the long-term results of botulinum toxin (BoNT-A) in women with iOAB.

METHODS

Patients treated with BoNT-A from 2004 until 2009 were evaluated in a non-academic teaching hospital (Zuyderland MC, Heerlen, the Netherlands). All female patients with a follow-up of >5 years with idiopathic bladder dysfunction were included. All patients received 200 U of onabotulinum toxin-A in 20 intradetrusor injections. In some patients, we applied a dose adjustment for repeated injections. Patients were instructed how to use clean intermittent self-catheterization (CISC) before the treatment. We advised patients to commence CISC if post-void residual exceeded 150 ml.

RESULTS

A total of 128 women were included. All patients had at least 5-year follow-up after their first injection. The mean follow-up was 97 (60-125) months. The mean age was 67 (46-88) years. Of all patients, 30 % were still on BoNT-A treatment at the last follow-up visit. Of the 70 % that discontinued treatment, 27 % had insufficient effect and 43 % had tolerability issues. Most patients discontinued treatment after the first (79 %) and second (19 %) injections. Only 2 % of patients discontinued treatment after more than two injections during follow-up.

CONCLUSION

Intravesical BoNT-A is an effective treatment for women with idiopathic OAB. However, in time, almost two-thirds of patients in our study discontinued therapy. Most patients discontinue treatment after one or two injections and mainly due to tolerability issues.

Eight-Year Experience With Botulinum Toxin Type-A Injections for the Treatment of Nonneurogenic Overactive Bladder: Are Repeated Injections Worthwhile?

Purpose:

To investigate the efficacy and safety of repeated botulinum toxin type-A (BTX-A) injections for patients with drug-refractory nonneurogenic overactive bladder (NNOAB) and explore factors predictive of outcome.

Methods:

Data were collected from all patients receiving repeated BTX-A injections for drug-refractory NNOAB between 2004 and 2012. Trigone-sparing injections were administered under sedation with antibiotic prophylaxis. Patient characteristics including age, sex, preoperative urodynamics, injection number, BTX-A dose, complications, and patient global impression of improvement (PGI-I) scores were collected. Correlations between patient factors and outcomes were assessed by using Pearson’s chi-square tests.

Results:

Fifty-two patients with a mean age of 67.4 years (range, 26–93 years) received 140 BTX-A injections in total; 33 (64%), 15 (29%), and 4 patients (7%) received 2, 3 to 4, and 5 to 8 injections, respectively. Mean follow-up time was 49 months (range, 9–101 months). Nine patients developed urinary tract infection; additionally, 3 patients experienced transient urinary retention. Median PGI-I score was 2 out of 7 (interquartile range [IQR], 2). For 46 patients, the PGI-I score remained stable with the administration of each injection. Pearson chi-square tests revealed that male patients or reduced bladder compliance was associated with a higher (worse) PGI-I score. Median PGI-I scores for men and women were 3 (IQR, 1) and 2 (IQR, 1), respectively; additionally, median PGI-I scores for those with normal bladder compliance and those with reduced bladder compliance were 2 (IQR, 2) and 4.5 (IQR, 1), respectively. Median PGI-I scores and complication rates were the same in the older patient (≥70 years) and younger (<70 years) patient cohorts.

Conclusions:

Efficacy is maintained with repeated BTX-A injections. Patients including the elderly show a good degree of tolerability with a low complication rate. Male patients or reduced bladder compliance is associated with poorer outcomes.

Overactive bladder - 18 years - Part II

Traditionally, the treatment of overactive bladder syndrome has been based on the use of oral medications with the purpose of reestablishing the detrusor stability. The recent better understanding of the urothelial physiology fostered conceptual changes, and the oral anticholinergics - pillars of the overactive bladder pharmacotherapy - started to be not only recognized for their properties of inhibiting the detrusor contractile activity, but also their action on the bladder afference, and therefore, on the reduction of the symptoms that constitute the syndrome. Beta-adrenergic agonists, which were recently added to the list of drugs for the treatment of overactive bladder, still wait for a definitive positioning - as either a second-line therapy or an adjuvant to oral anticholinergics. Conservative treatment failure, whether due to unsatisfactory results or the presence of adverse side effects, define it as refractory overactive bladder. In this context, the intravesical injection of botulinum toxin type A emerged as an effective option for the existing gap between the primary measures and more complex procedures such as bladder augmentation. Sacral neuromodulation, described three decades ago, had its indication reinforced in this overactive bladder era. Likewise, the electric stimulation of the tibial nerve is now a minimally invasive alternative to treat those with refractory overactive bladder. The results of the systematic literature review on the oral pharmacological treatment and the treatment of refractory overactive bladder gave rise to this second part of the review article Overactive Bladder - 18 years, prepared during the 1st Latin-American Consultation on Overactive Bladder.

Current and potential urological applications of botulinum toxin A

Botulinum toxin subtype A (BoNT-A) is a potent neurotoxin that can selectively modulate neurotransmitter release from nerve endings, resulting in muscular paralysis. BoNT-A might also act on sensory nerves, and have an anti-inflammatory effect. In the first urological use of BoNT-A, injection into the urethral sphincters of patients with detrusor-sphincter dyssynergia resulted in a reduction of urethral resistance and improved voiding efficiency. Subsequently, intravesical BoNT-A injections have received regulatory approval for treatment of neurogenic detrusor overactivity owing to spinal cord lesions or multiple sclerosis, and idiopathic overactive bladder in adults. BoNT-A has also been widely used to treat patients with the off-label indications of neurogenic or non-neurogenic voiding dysfunction and male lower urinary tract symptoms owing to BPH and bladder-neck dysfunction. Other indications for which urologists have applied BoNT-A injections include interstitial cystitis/bladder pain syndrome, bladder oversensitivity and chronic pelvic pain syndrome. BoNT-A is currently delivered as an intravesical injection; however, use of liposome encapsulated formulations is also beginning to show some therapeutic potential.

Botulinum toxin for symptomatic therapy in multiple sclerosis

Botulinum toxin (BT) is a neurotoxin that paralyzes muscles by inhibiting release of acetylcholine from presynaptic vesicles at the neuromuscular junction. In people with multiple sclerosis (MS), clinical experience and research studies show that local injection of minute quantities of BT can temporarily control skeletal muscle spasticity, bladder detrusor hyperreflexia, and tremor. Specifically, BT injections have been shown to reduce muscle tone and improve passive function, and possibly improve active function, in patients with spasticity. Injection of BT into the bladder wall is a uniquely effective, safe, and durable treatment in patients with neurogenic detrusor hyperreflexia due to MS who have insufficient response or who do not tolerate oral antimuscarinic medications. This procedure has markedly reduced the need for indwelling catheters and bladder surgery. In addition, a recent study suggests BT may be effective for select patients with MS-associated upper extremity tremor. Appropriate use of BT can improve quality of life for many patients with MS.