Understanding the Role of Botulinum Toxin A in the Treatment of the Overactive Bladder—More than Just Muscle Relaxation

Neurogenic bladder - concepts and treatment recommendations

Introduction:

Bladder and urinary sphincter malfunctioning that results from some change in the central and/or peripheral nervous system is defined as neurogenic bladder. The urinary tract symptoms that can be related to its filling, emptying, or both have a significant impact on the quality of life of individuals. The present review was based on the document prepared for the public health system in Brazil as a treatment guidelines proposal.

Material and Methods:

Survey questions were structured as per PICO (Population, Intervention, Control, and Outcome). Search strategies were defined and performed in the MEDLINE/Pubmed, Embase, Epistemonikos and Google Scholar databases. The selection of articles followed the evidence hierarchy concept; evidence body was identified, and the quantitative study data were extracted. The quality of evidence and grade of recommendation were qualitatively assessed according to GRADE (Grading of Recommendations, Assessment, Development and Evaluations).

Results:

A total of 2.707 articles were identified, with 49 of them being selected to compose the basis for this review. Neurogenic bladder treatments were classified according to their focus on filling or emptying symptoms and sub- classified in pharmacological and surgical treatments.

Conclusion:

Treatment guidelines are important tools for the public health system to promote the best practice when treating neurogenic bladder patients.

Natural Antispasmodics: Source, Stereochemical Configuration, and Biological Activity

Natural products with antispasmodic activity have been used in traditional medicine to alleviate different illnesses since the remote past. We searched the literature and compiled the antispasmodic activity of 248 natural compounds isolated from terrestrial plants. In this review, we summarized all the natural products reported with antispasmodic activity until the end of 2017. We also provided chemical information about their extraction as well as the model used to test their activities. Results showed that members of the Lamiaceae and Asteraceae families had the highest number of isolated compounds with antispasmodic activity. Moreover, monoterpenoids, flavonoids, triterpenes, and alkaloids were the chemical groups with the highest number of antispasmodic compounds. Lastly, a structural comparison of natural versus synthetic compounds was discussed.

Intradetrusor onabotulinumtoxinA injections are significantly more efficacious than oral oxybutynin for treatment of neurogenic detrusor overactivity: results of a randomized, controlled, 24-week trial

OBJECTIVE

To prospectively compare the results of intradetrusor onabotulinumtoxinA injections and oral oxybutynin for urinary continence, urodynamic parameters and quality of life in patients with neurogenic detrusor overactivity due to spinal cord injury.

METHODS

Adult patients under intermittent catheterization were randomized 1:1 to receive one injection of onabotulinumtoxinA 300U or oxybutynin 5mg, per oris, three times/day. Primary study endpoint was change in urinary incontinence episodes/24 hours and secondary study endpoints were maximum cystometric capacity, maximum detrusor pressure, bladder compliance and quality of life before randomization and at week 24.

RESULTS

Sixty-eight patients participated in the trial. Significant improvements in urinary incontinence per 24 hours, all investigated urodynamic parameters and quality of life were observed in both groups. Compared with oral oxybutynin, onabotulinumtoxinA was significantly more efficacious for all parameters investigated. Non-response to treatment was higher for oral oxybutynin (23.5%) than onabotulinumtoxinA (11.8%). Dry mouth was the most common adverse in patients with oral oxybutynin (72%) and transient macroscopic hematuria in patients with onabotulinumtoxinA (28%). Only one patient with oral oxybutynin dropped out the study because of adverse effects.

CONCLUSION

The comparison of the two study drugs showed that onabotulinumtoxinA was significantly more efficacious than oral oxybutynin with regard to continence, urodynamic parameters and quality of life. Clinicaltrials.gov: NCT:01477736.

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.

Engineered botulinum neurotoxins as new therapeutics

Botulinum neurotoxins (BoNTs) cause flaccid paralysis by inhibiting neurotransmission at cholinergic nerve terminals. Each BoNT consists of three domains that are essential for toxicity: the binding domain, the translocation domain, and the catalytic light-chain domain. BoNT modular architecture is associated with a multistep mechanism that culminates in the intracellular proteolysis of SNARE (soluble N-ethylmaleimide-sensitive-fusion-protein attachment protein receptor) proteins, which prevents synaptic vesicle exocytosis. As the most toxic proteins known, BoNTs have been extensively studied and are used as pharmaceutical agents to treat an increasing variety of disorders. This review summarizes the level of sophistication reached in BoNT engineering and highlights the diversity of approaches taken to utilize the modularity of the toxin. Improved efficiency and applicability have been achieved by direct mutagenesis and interserotype domain rearrangement. The scope of BoNT activity has been extended to nonneuronal cells and offers the basis for novel biomolecules in the treatment of secretion disorders.

Botulinum toxin in neurogenic detrusor overactivity

Purpose

To evaluate the effects of botulinum toxin on urodynamic parameters and quality of life in patients with neurogenic detrusor overactivity.

Methods

Thirty four adult patients with spinal cord injury and detrusor overactivity were selected. The patients received 300 units of botulinum toxin type A. The endpoints evaluated with the episodes of urinary incontinence and measured the maximum cystometric capacity, maximum amplitude of detrusor pressure and bladder compliance at the beginning and end of the study (24 weeks) and evaluated the quality of life by applying the Qualiveen questionnaire.

Results

A significant decrease in the episodes of urinary incontinence was observed. All urodynamic parameters presented a significant improvement. The same was observed in the quality of life index and the specific impact of urinary problems scores from the Qualiveen questionnaire. Six patients did not complete the study, two due to incomplete follow-up, and four violated protocol and were excluded from the analyses. No systemic adverse events of botulinum toxin type A were reported.

Conclusions

A botulinum toxin type A showed a significantly improved response in urodynamics parameters and specific and general quality of life.

Neurogenic detrusor overactivity treated with english botulinum toxin a: 8-year experience of one single centre

OBJECTIVE

Determine long-term effect of English botulinum neurotoxin type A (BoNTA; Dysport) for refractory neurogenic detrusor overactivity (NDO) for possible reduction of BoNTA efficacy after repeated injections.

METHODS

Between 1999 and 2005, 199 patients with spinal cord lesions with refractory NDO were treated with Dysport. All patients underwent a clinical examination, urinalysis, and videourodynamic study at baseline and at 3, 6, and 12 mo after each treatment, as well as a visual analogue scale (VAS) assessment and a bladder diary checked for 1 wk before each visit. We used 1000, 750, 500 IU BoNTA at the beginning of our experience, and thereafter we mainly used 750 IU. Outcome measures included frequency of urge urinary incontinence (Incontinence Episode Frequency [IEF] test); urodynamic parameters including maximum cystometric bladder capacity (MCBC), reflex volume (RV), bladder compliance (BC); number of pads/condoms; antimuscarinic drug consumption; short- and long-term side-effects; and quality of life measured with VAS.

RESULTS

No statistically significant differences were found in efficacy duration with the three Dysport doses (p=0.5274). The difference between the intervals of injections was not statistically significant (p=0.2659). MCBC, RV, and BC improved significantly after treatment compared with baseline values (p<0.001) and there were no statistically significant differences after each retreatment or regarding Dysport dose (p>0.05). There was a significant improvement in patient satisfaction after each retreatment as expressed on the VAS (p<0.001). There was a significant reduction in IEF score and pads/condoms use in the first 4 wk after each treatment (p<0.0001).

CONCLUSION

After repeated injections the effect of BoNTA remained constant.