Injectable neuromodulatory agents: botulinum toxin therapy

Botulinum toxin in low urinary tract disorders - over 30 years of practice (Review)

Botulinum toxin is a substance produced by Clostridium Botulinum and is responsible for human botulism. This substance is a poison, a neurotoxin, but used in limited quantities it can be a cure for some diseases. It is well connected to a large variety of medical applications. The mechanism of action relies on blocking the acetylcholine at the neuromuscular junction, which blocks the transmission of the nervous impulse with secondary flaccid paralysis. In urology, its role in idiopathic overactive bladder and neurogenic bladder is well known. We performed a thorough review using PubMed and other databases, revising the mechanisms of botulinum toxin action in urologic pathology, treatment procedures and other options. Botulinum toxin is a well-studied substance with a large number of applications in medicine. In urologic pathology, overactive bladder and neurogenic bladder are backed by robust studies that support the therapeutic role of this substance. The toxin has multiple effects, such as inhibition of the nerve growth factor, blocking the bladder sensory afferent pathway and apoptotic effect on the prostate tissue, by inhibiting the substance P, altering the nociceptive pathways. Interstitial cystitis and other rare pathologies show promising results, but further studies are needed. The role of botulinum toxin in benign prostatic hyperplasia is still not elucidated.

A systematic review and meta-analysis of effectiveness and safety of therapy for overactive bladder using botulinum toxin A at different dosages

Purpose

To assess the effectiveness and safety of botulinum toxin A (BTX-A) at different dosages for overactive bladder (OAB).

Materials and Methods

The MEDLINE, EMBASE, and Cochrane Controlled Trials Register databases were searched through November 3, 2016 to identify relevant randomized controlled trials (RCTs).

Results

Eleven studies were identified in this meta-analysis. Compared with placebo, the urinary incontinence (UI) episodes per week as the primary outcomes, urodynamic parameters including maximum cystometric capacity (MCC), and maximum detrusor pressure (MDP) for neurogenic detrusor overactivity (NDO) at 6 weeks, and for idiopathic detrusor overactivity (IDO) at 36 weeks were evaluated. These and other outcomes for effectiveness of BTX-A at different dosages in two observation periods indicate that a dose greater than 50 U is significantly more effective for certain symptoms of OAB compared with placebo. However, there were no significant differences between some dosages. Compared with placebo, the outcomes of total adverse events for NDO and for IDO show that doses of 300 U and 200 U for NDO are associated with more complications.

Conclusions

In consideration that the treatments of BTX-A were with minimal, local, and manageable adverse effects, this meta-analysis demonstrates that BTX-A 200 U is recommended for management of NDO for short-term treatment for there was no significant difference from the larger dose of 300U. The short-term efficacies of BTX-A for IDO remain to be investigated.

Botulinum Toxin A Injections Into Pelvic Floor Muscles Under Electromyographic Guidance for Women With Refractory High-Tone Pelvic Floor Dysfunction: A 6-Month Prospective Pilot Study

OBJECTIVES

High-tone pelvic floor dysfunction (HTPFD) is a debilitating chronic pain disorder for many women with significant impact on their quality of life (QoL). Our objective was to determine the efficacy of electromyography-guided onabotulinumtoxinA (Botox; Allergan, Irvine, Calif) injections in treating patient's perception of pelvic pain and improving QoL measurement scores.

METHODS

This is a prospective pilot open-label study of women with chronic pelvic pain and HTPFD who have failed conventional therapy between January 2011 and August 2013. Botox injections (up to 300 U) were done using needle electromyography guidance, from a transperineal approach, to localize spastic pelvic floor muscles (PFMs). Data were collected at baseline, 4, 8, 12, and 24 weeks after injections. This included demographics; Visual Analog Scale (VAS) scores for pain and dyspareunia; validated questionnaires for symptoms, QoL, and sexual function; Global Response Assessment scale for pelvic pain; digital examination of PFM for tone and tenderness; and vaginal manometry. Side effects were also recorded.

RESULTS

Out of 28 women who enrolled in the study, 21 completed the 6-month follow-up and qualified for analysis. The mean (SD) age was 35.1 (9.4) years (range, 22-50 years), and the mean (SD) body mass index was 25 (4.4). Comorbidities included interstitial cystitis/bladder pain syndrome (42.9%) and vulvodynia (66.7%). Overall, 61.9% of subjects reported improvement on Global Response Assessment at 4 weeks and 80.9% at 8, 12, and 24 weeks post injection, compared with baseline. Of the subjects who were sexually active at baseline, 58.8% (10/17), 68.8% (11/16), 80% (12/15), and 83.3% (15/18) reported less dyspareunia at 4, 8, 12, and 24 weeks, respectively. Dyspareunia Visual Analog Scale score significantly improved at weeks 12 (5.6, P = 0.011) and 24 (5.4, P = 0.004) compared with baseline (7.8). Two of the 4 patients who avoided sexual activity at baseline secondary to dyspareunia resumed and tolerated intercourse after Botox. Sexual dysfunction as measured by the Female Sexual Distress Scale significantly improved at 8 weeks (27.6, P = 0.005), 12 weeks (27.9, P = 0.006), and 24 weeks (22.6, P < 0.001) compared with baseline (34.5). The Short-Form 12 Health Survey (SF-12) showed improved QoL in the physical composite score at all post injections visits (42.9, 44, 43.1, and 45.5 vs 40 at baseline; P < 0.05), and in the mental composite score at both 12 and 24 weeks (44.3 and 47.8 vs 38.5, P = 0.012). Vaginal manometry demonstrated significant decrease in resting pressures and in maximum contraction pressures at all follow-up visits (P < 0.05). Digital assessment of PFM (on a scale from 0 to 4) showed decreased tenderness on all visits (mean of 1.9, 1.7, 1.8, 1.9; P < 0.001) compared with baseline (2.8). Reported postinjection adverse effects included worsening of the following preexisting conditions: constipation (28.6%), stress urinary incontinence (4.8%), fecal incontinence (4.8%), and new onset stress urinary incontinence (4.8%).

CONCLUSIONS

Electromyography-guided Botox injection into PFM could be beneficial for women with refractory HTPFD who have failed conservative therapy.

Refractory overactive bladder: Beyond oral anticholinergic therapy

Objectives:

In this review, we discuss the treatment of refractory overactive bladder (OAB) that has not adequately responded to medication therapy and we propose an appropriate care pathway to the treatment of OAB. We also attempt to address the cost of OAB treatments.

Materials and Methods:

A selective expert review of the current literature on the subject of refractory OAB using MEDLINE was performed and the data is summarized. We also review our experience in treating refractory OAB. The role and outcomes of various treatment options for refractory OAB are discussed and combined therapy with oral anticholinergics is explored. Emerging remedies including intravesical botulinum toxin injection and pudendal neuromodulation are also reviewed, along with conventional surgical options.

Results:

In general behavioral therapy, pelvic floor electrical stimulation, magnetic therapy and posterior tibial nerve stimulation (PTNS), have shown symptom decreases in 50-80% of patients with OAB. Depending on the study, combination therapy with oral anticholinergics seems to improve efficacy of behavioral therapy and PTNS in approximately 10-30%. In multicenter, long-term randomized controlled trials, sacral neuromodulation has been shown to improve symptoms of OAB and OAB incontinence in up to 80% of the patients treated. Studies involving emerging therapies such as pudendal serve stimulation suggest that there may be a 15-20% increase in efficacy over sacral neuromodulation, but long-term studies are not yet available. Another emerging therapy, botulinum toxin, is also showing similar success in reducing OAB symptoms in 80-90% of patients. Surgical approaches, such as bladder augmentation, are a last resort in the treatment of OAB and are rarely used at this point unless upper tract damage is a concern and all other treatment options have been exhausted.

Conclusion:

The vast majority of OAB patients can be managed successfully by behavioral options with or without anticholinergic medications. When those fail, neuromodulation or intravesical botulinum toxin therapies are successful alternatives for most of the remaining group. We encourage practitioners responsible for the care of OAB patients to gain experience with these options. More research is needed to assess the cost-effectiveness of various OAB treatments

Subcutaneous tunneling of the temporary testing electrode significantly improves the success rate of subchronic sacral nerve modulation (SNM)

Sacral nerve modulation (SNM) is an effective way to treat non-neurogenic dysfunctions of pelvic organs. For over 20 years, this technique has been used for the treatment of overactive bladder, urinary retention, pelvic pain and even more recently, fecal incontinence and constipation. The objective of the study is to improve the fixation of the temporary testing electrode (TTE) in order to obtain more reliable results in the testing phase which should lead to have a comparable success rate as the two-stage implant for a chronic implant. Twenty-eight patients (ratio of sex women:men = 3:1; with overactive bladder, urinary retention, pelvic pain syndrome and fecal incontinence) were evaluated by the modified temporary test electrode (TTE) placement. With the subcutaneous tunneling technique (mean time of evaluation 8.3 days), it is possible to perform percutaneous nerve evaluation (PNE) more effectively with an objective, reliable and less expensive outcome prior to the implantation of the implantable sacral nerve stimulator in almost 80% of the evaluated patients. Because the costs of therapy are not covered by health insurance in all countries, there is a need for an effective and inexpensive way to test and select patients appropriately. The tunneled TTE maintains its place for consistent amplitude during the entire test duration. The modification of placing the TTE produces repayable results. This technique can be performed on an outpatient basis to evaluate sacral nerve modulation as an early treatment option for non-dysfunctions of pelvic organs before they are forwarded to a specialized center for a chronic SNM implantation.

Intradetrusor injection of botulinum-A toxin in patients with idiopathic and neurogenic detrusor overactivity: Urodynamic outcome and patient satisfaction

PURPOSE

To assess and compare the efficacy of botulinum-A toxin (BTX-A) injections into the detrusor in idiopathic and neurogenic detrusor overactivity (IDO and NDO) resistant to anticholinergic treatment with respect to patient satisfaction.

PATIENTS AND METHODS

In a prospective study, 16 patients with IDO and 14 with NDO resistant to anticholinergic treatment were injected with 500 U of Dysport into the detrusor. Clinical, urodynamic, and satisfaction assessments were performed at baseline and after BTX-A injections.

RESULTS

In IDO as well as in NDO, there was a significant increase in median maximum cystometric capacity (MCC) from 177.5 to 262.5 ml (P<0.0005) and 160 to 270 ml (P=0.001), median bladder compliance from 24.5 to 40.0 ml/cmH2O (P<0.0005) and 25.5 to 44.0 ml/cmH2O (P=0.001) and median PVR from 15 to 80 ml (P=0.001) and 15.0 to 62.5 ml (P=0.001), respectively. Median Pdet max decreased significantly from 49 to 37 cmH2O (P<0.0005) and 48.5 to 37.0 cmH2O (P=0.001), and median Pdet Qmax from 32.0 to 20.0 ml/sec (P<0.0005) and 36.0 to 21.5 ml/sec (P=0.001), respectively. The effect of BTX-A injections lasted for a median time of 5 months in both groups. Median daytime frequency, nocturia, and number of used pads decreased significantly in both groups. More than 80% of the patients were satisfied with the effect of BTX-A.

CONCLUSIONS

Patients with intractable IDO respond to intradetrusor BTX-A with a significant and comparable but temporally limited effect in urodynamic and LUTS parameters as those with NDO. The majority of patients were satisfied with treatment.

Botulinum toxin: A potential alternative to current treatment of neurogenic and idiopathic urinary incontinence due to detrusor overactivity

OBJECTIVE

To analyze and report the current data on the treatment of both neurogenic and idiopathic detrusor overactivity with Botulinum toxin.

METHODS

Literature review using Pub-Med and Medline from 1990 until June 30, 2006.

RESULTS

Case series of patients with neurogenic detrusor dysfunction (NDD) and idiopathic detrusor overactivity (IDO) range from 15 to 200 patients with follow up from 12 to 36 weeks post-treatment. Significant improvements in cystometric bladder capacity, reflex volume at first urge to void, and bladder compliance are seen in nearly all patients. Approximately 50% of NDD patients achieved urinary continence and almost all had improvement in bladder control up to 36 weeks following treatment. Patients with IDO with urgency alone or with incontinence also had urodynamic as well as symptom improvement. Approximately 75% of patients with IDO and incontinence are dry at 12 weeks post-treatment. Urgency disappears on average in two thirds of patients. Quality of life scores also shows significant improvement for all groups.

CONCLUSION

Botulinum toxin-A has emerged as a promising option for the treatment of neurogenic and refractory idiopathic detrusor overactivity. Studies to date have shown that not only is this treatment effective at decreasing urinary symptoms and incontinence, as well as improving potentially dangerous urodynamic measures, but it is also minimally invasive, reversible and safe. Questions over proper dosing and dilution, number of injection sites, and re-injection rates remain to be answered.

Successful Treatment with Intradetrusor Botulinum-A Toxin for Urethral Urinary Leakage (Catheter Bypassing) in Patients with End-Staged Multiple Sclerosis and Indwelling Suprapubic Catheters

OBJECTIVE

To present the initial results of Botulinum-A toxin (BTA) injection in patients with long-standing multiple sclerosis (MS) and urethral leakage of urine in spite of indwelling suprapubic catheters (catheter bypassing).

METHODS

Study of three patients treated with cystoscopic injection of BTA IU (Allergan). Telephone interviews were made at four- to six-week intervals. Continence status and patient satisfaction were recorded before and after treatment.

RESULTS

Patient 1 remained dry at 48 weeks post injection. Patient 2 became incontinent again after 40 weeks. The third patient was continent when interviewed at 27 weeks following injection, but died two weeks later. The patients were very satisfied with the procedure and there were no complications related to BTA.

CONCLUSIONS

Intradetrusor BTA injection is a very effective and safe treatment for intractable catheter bypassing in patients with neurogenic detrusor overactivity.

Overactive Bladder: A Better Understanding of Pathophysiology, Diagnosis and Management

PURPOSE

We reviewed current information regarding the updated definitions, prevalence, etiologies, disease burden, and management of OAB from a number of perspectives, including professional impact and patient quality of life.

MATERIALS AND METHODS

Published literature and current treatment concepts were reviewed regarding the understanding and management of OAB.

RESULTS

OAB is a symptom syndrome including urinary urgency with or without urinary incontinence, usually with frequency and nocturia. Approximately 17% of the adult population experience OAB. There are evolving theories regarding its pathophysiology and the mechanism of action of the most commonly prescribed pharmacological therapy (antimuscarinic agents). Treatment primarily revolves around improving quality of life.

CONCLUSIONS

Behavioral therapy combined with pharmacological therapy often will bring about acceptable outcomes for patients with OAB. Modalities such as botulinum toxin injections, neuromodulation, and various surgical interventions also are showing encouraging results in more refractory patients.

Urologic applications of botox

Botulinum toxin (BTX), a neurotoxin produced by the gram-positive, rod-shaped anaerobic bacterium Clostridium botulinum, was isolated in 1897 by Belgian scientist Professor Pierre Emile van Ermengem. BTX acts by blocking the release of acetylcholine at the neuromuscular junction. As a result of this chemodenervation, a temporary flaccid paralysis ensues. Different medical disciplines have taken advantage of this temporary paralysis to treat muscular hypercontraction. BTX was first approved by the US Food and Drug Administration in 1989 for use in patients with strabismus and blepharospasm. Since then, BTX has been used to treat a number of different neuromuscular disorders. Although not approved by the US Food and Drug Administration, BTX has been used successfully in urology to treat neurogenic and non-neurogenic detrusor overactivity, detrusor-sphincter dyssynergia, motor and sensory urge, and chronic pain syndromes.