RimabotulinumtoxinB in sialorrhea: systematic review of clinical trials

Overcoming clozapine's adverse events: a narrative review of systematic reviews and meta-analyses

INTRODUCTION

Clozapine is the gold standard treatment for treatment-resistant schizophrenia, however adverse events remain a clinical challenge.

AREAS COVERED

This review presents a narrative synthesis of systematic reviews and meta-analyses that have reported the onset, incidence, prevalence, and management of clozapine's adverse events. We conducted a systematic literature search using PubMed, Embase, PsycINFO, OvidMEDLINE, CINAHL, and the Cochrane Database of Systematic Reviews from inception to April 2024.

EXPERT OPINION

Effective management of clozapine's adverse events necessitates multi-faceted, individualized, and shared-decision strategies. Despite a lack of high-quality systematic evidence, expert inter-disciplinary solutions are provided to help address a critical need for clinical guidance. This 35-year update offers an evidence-based framework to assist clinicians, patients, and caregivers navigate the adverse events associated with clozapine therapy.

Botulinum neurotoxin type A in the interdisciplinary treatment of sialorrhea in adults and children-update and practice recommendations

Sialorrhea is defined as a chronic excessive flow of saliva from the mouth, often with adverse consequences for health and quality of life of patients. In addition to currently used non-drug treatment and systemic drugs, intraglandular Botulinum Neurotoxin A (BoNT/A) injections have been examined in case studies, controlled trials and clinical practice. Two pivotal Phase III trials recently led to market approval in the USA and EU for IncobotulinumtoxinA [Xeomin®, IncoBoNT/A, Clostridium botulinum neurotoxin type A (150 kD), free from complexing proteins, Merz Pharmaceuticals GmbH] for treatment of chronic sialorrhea in adults and pediatric patients. This review provides a multidisciplinary approach to discuss the current state of sialorrhea therapy as well as benefits and current limitations of BoNT/A injections. A consensus regarding treatment recommendations made available to physicians in Germany in 2022 has now been updated here for presentation to an international audience. This review provides a framework including a flow chart for patient selection, recommendations for dosing and the injection process, as well as a discussion of therapeutic goals, long-term benefits and safety aspects. This review is aimed at supporting physicians in developing multidisciplinary and individualized treatment approaches to achieve optimal benefits for patients.

Effectiveness of the pharmacological treatments for sialorrhea in patients with Parkinson's disease: a systematic review and network meta-analysis

OBJECTIVES

The present systematic review and network meta-analysis of randomized control trials (RCTs) aimed to establish whether there are evidence-based differences in the pharmacological agents used to manage sialorrhea in patients with Parkinson's disease (PD).

MATERIAL AND METHODS

The authors searched the databases: MEDLINE via PubMed, EMBASE, Scopus, Web of Science, and Cochrane Library for clinical trials. Unpublished trials were searched on clinicaltrials.gov and the Brazilian Clinical Trials Registry. Means and standard deviations of changes in the salivary flow or drooling reported by participants due to the interventions were recorded.

RESULTS

The authors analyzed 13 RCTs. Compared to the placebo, types A and B of the botulinum toxin effectively reduced the salivary flow and the severity or frequency of drooling. However, the network meta-analysis did not differentiate between the botulinum toxin types. Ipratropium bromide and glycopyrrolate did not differ from the placebo. Indirect evidence showed that ipratropium had similar results to those obtained with both types of botulinum toxin. The CINeMA approach estimated the quality of the evidence as very low for all comparisons.

CONCLUSION

The best treatment for sialorrhea in patients with PD is not fully elucidated yet. Therefore, more well-conducted randomized clinical trials are required to increase the level of evidence.

CLINICAL RELEVANCE

There needs to be more evidence defining the best intervention to treat sialorrhea in patients with PD. However, botulinum toxin types A and B seem to reduce sialorrhea in patients effectively.

Pharmacological Interventions for Sialorrhoea in People with Parkinson's Disease: A Systematic Review and Meta-Analysis

Background/objectives

Sialorrhoea is a common non motor complication experienced by people with Parkinson's disease (PD). Despite its prevalence there is conflicting evidence on how to effectively treat it. Our aim was to establish the efficacy and safety outcomes of pharmacological interventions used to treat sialorrhoea in people with idiopathic PD.

Methods

We registered and conducted a systematic review and meta-analysis (PROSPERO: CRD42016042470). We searched seven electronic databases from inception until July 2022. Quantitative synthesis was performed where data allowed using random effects models.

Results

From 1374 records we included 13 studies (n = 405 participants). Studies were conducted in Europe, North America and China. There was marked heterogeneity in the interventions used, follow up times and outcome measures investigated. The main source of risk of bias identified was reporting bias. Five studies were included in the quantitative synthesis. Summary estimates showed administration of botulinum toxin significantly reduced saliva production, improved patient reported functional outcomes and was associated with an increase in adverse events.

Conclusion

Sialorrhoea in PD is an important condition, but current data does not allow for strong recommendations on optimal pharmacological treatments. There is significant heterogeneity in outcomes measures used to evaluate the burden of sialorrhoea with lack of consensus on what constitutes clinically meaningful change. More research is required to better understand the underlying mechanism and potential treatments of sialorrhoea in idiopathic PD.

[Therapy of Sialorrhea with Botulinum Toxin - An Update]

The most important salivary glands are the paired parotid and submandibular glands. Adults produce 1 to 1.5 liters of saliva which are then regularly swallowed. When the act of swallowing is disturbed, salivation occurs. More rarely, the cause can be found in increased saliva production, for example, when caused through medication. Sialorrhea impairs the quality of life substantially and is frequently often socially stigmatizing. Therapy includes conservative measures such as functional dysphagia therapy, oral or transdermal application of anticholinergics, as well as, in selected cases, radiation and surgical measures. Over the last 20 years, local injection of botulinum toxin has been successfully applied in the treatment of this condition. With approval of incobotulinumtoxinA toxin for children and adults, this procedure will become the therapy of choice for chronic sialorrhea. The results of the phase III registration trials have demonstrated high efficacy and good safety of the injection treatment in both children and adults.

Botulinum Toxin Injections for Treatment of Drooling in Children with Cerebral Palsy: A Systematic Review and Meta-Analysis

Background: We aimed to review and analyse the effectiveness and safety of botulinum toxin type A (BoNT-A) injections for drooling in children with cerebral palsy. Data sources: We searched the EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) databases from inception to January 2020. Methods: We included randomized controlled trials and observational studies which (1) involved children with cerebral palsy, (2) used BoNT-A for control of drooling, and (3) provided quantitative evaluations of drooling before and after intervention with BoNT-A. Results: Twenty-one trials met the inclusion criteria. Most studies showed that BoNT-A injections are safe and efficacious as a treatment for drooling in children with cerebral palsy. Four trials had sufficient data to pool the results for the meta-analysis. Both the drooling quotient (p = 0.002) and drooling Ffrequency and severity scale (p = 0.004) supported this conclusion. Conclusion: BoNT-A injections are a safe, reversible, effective treatment for drooling control in children with cerebral palsy that can offer effectiveness for more than 3 months with few side effects. The dosage of BoNT-A should not exceed 4 units/kg. Further studies are required to determine the optimal dosage and target glands.

Efficacy and safety of botulinum toxin for treating sialorrhea: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Sialorrhea often happens in patients with neurologic disorders, and botulinum toxin (BoNT), which inhibits acetylcholine activation, may be an effective treatment for drooling. This systematic review and meta-analysis of randomized control trials aims to evaluate the efficacy and safety of BoNT in adults and children with sialorrhea due to neurological disorders.

METHODS

The PubMed, Embase, and Cochrane databases were searched for relevant studies published before August 2021. The pooled estimate of outcomes was calculated using a random effect model.

RESULTS

The review included 17 studies involving 981 patients. Compared with placebo, both BoNT type A (BoNT-A) and BoNT type B (BoNT-B) alleviated drooling frequency and severity (mean difference, 95% CI; BoNT-A: -1.20, -1.89 to -0.51; BoNT-B: -1.62, -2.07 to -1.17), reduced saliva weight (BoNT-A: -1.70, -2.30 to -1.10; BoNT-B: -1.12, -1.97 to -0.27), and improved global impression of change (BoNT-A: -1.30, -1.73 to -0.86; BoNT-B: -1.58, -1.95 to -1.21) in adults 4 weeks postinjection. BoNT-B remained effective at 12 weeks. In children, BoNT-A and BoNT-B alleviated sialorrhea symptoms (BoNT-A: -1.63, -2.42 to -0.85; BoNT-B: -5.20, -6.03 to -4.37) and BoNT-A reduced saliva weight (-0.77, -1.54 to 0.00) at 4 weeks postinjection. After 12 weeks, BoNT-B remained efficacious. Most adverse effects (AEs) were mild to moderate and self-limited.

CONCLUSIONS

There is moderate certainty of evidence (COE) that either BoNT-A or BoNT-B could relieve sialorrhea after 4 and 12 weeks of follow-up without significantly more severe AEs in adults. However, the COE is very low to low in children.

Sialorrhea in Parkinson's Disease

Sialorrhea, or excessive saliva beyond the margin of the lip, is a common problem in many neurological diseases. Previously, sialorrhea has been underrecognized in Parkinson’s disease (PD) patients. Despite this, many patients rank sialorrhea as one of the most debilitating complaints of Parkinson’s disease. Previous treatment for sialorrhea has been suboptimal and has been plagued by significant side effects that are bothersome and can be dangerous in patients with a concurrent neurodegenerative disease. This review sought to review the anatomy, function, and etiology of sialorrhea in PD. It then sought to examine the evidence for the different treatments of sialorrhea in PD, and further examined newer evidence for safety and efficacy in minimally invasive treatment such as botulinum toxin.

Safety and Efficacy of RimabotulinumtoxinB for Treatment of Sialorrhea in Adults: A Randomized Clinical Trial

Question

Are rimabotulinumtoxinB injections safe and effective for management of sialorrhea in adults?

Findings

In this randomized clinical trial of 187 adults with sialorrhea, rimabotulinumtoxinB injections (2500 U and 3500 U) appeared to statistically significantly reduce sialorrhea vs placebo (treatment effect, −0.30 for both doses vs placebo, P < .001). Therapeutic benefits were seen as early as 1 week after injection and persisted for 11 to 15 weeks.

Meaning

RimabotulinumtoxinB is a safe, effective, and well-tolerated treatment for sialorrhea in adults.

Importance

RimabotulinumtoxinB (RIMA) may be preferable as an anti-sialorrhea treatment compared with current oral anticholinergic drugs in people with neurological disorders.

Objective

To assess the safety, efficacy, and tolerability of RIMA injections for the treatment of sialorrhea in adults.

Design, Setting, and Participants

This randomized, parallel, double-blind, placebo-controlled clinical trial of RIMA 2500 U and 3500 U was conducted from November 14, 2013, to January 23, 2017. A total of 249 adult patients with troublesome sialorrhea secondary to any disorder or cause were screened. Of them, 13 refused further participation in the study or were lost to follow-up and 49 did not fulfill the criteria for participation; 187 were ultimately enrolled. Patients had to have a minimum unstimulated salivary flow rate (USFR) of 0.2 g/min and a minimum Drooling Frequency and Severity Scale score of 4.

Exposures

Patients were randomized 1:1:1 to RIMA, 2500 U (n = 63); RIMA, 3500 U (n = 64); or placebo (n = 60).

Main Outcomes and Measures

Primary outcomes were the change in USFR from baseline to week 4 and the Clinical Global Impression of Change (CGI-C) at week 4. The CGI-C scores were recorded on a 7-point scale ranging from very much improved to very much worse. Adverse events were recorded throughout the trial period.

Results

Of 187 patients enrolled (147 men [78.6%]; mean [SD] age, 63.9 [13.3] years), 122 patients had Parkinson disease (65.2%), 13 (7.0%) were stroke survivors, 12 had amyotrophic lateral sclerosis (6.4%), 6 had medication-induced sialorrhea (3.2%), 4 had adult cerebral palsy (2.1%), and 30 had sialorrhea owing to other causes (16.0%). A total of 176 completed the study. Treatment with both doses of RIMA significantly reduced USFR at week 4 vs placebo (mean treatment difference, −0.30 g/min [95% CI, −0.39 to −0.21] for both doses vs placebo, P < .001). The CGI-C scores were statistically significantly improved at week 4 for both treatment groups vs placebo (−1.21 [95% CI, −1.56 to −0.87] for 2500 U, −1.14 [95% CI, −1.49 to −0.80] for 3500 U, both P < .001). Treatment benefits were seen as early as 1 week after injection and were maintained over the treatment cycle of approximately 13 weeks. The RIMA injections were well tolerated compared with placebo. The most common adverse events were self-limited mild to moderate dry mouth, dysphagia, and dental caries.

Conclusions and Relevance

Treatment with RIMA (2500 U and 3500 U) in adults was well tolerated and reduced sialorrhea, with the onset of the effect at 1 week after the injection. These data support the clinical use of RIMA in the management of sialorrhea in adults.

Trial Registration

ClinicalTrials.gov Identifier: NCT01994109

Therapy of Sialorrhea with Botulinum Neurotoxin

Botulinum neurotoxin (BoNT) is considered the treatment of choice for various symptoms and diseases such as focal dystonia and focal spasticity. The effects of BoNT on the salivary glands have also been known for years, but their use was limited because of a lack of approval studies. Now the indication of sialorrhea is approved in some countries for incobotulinumtoxinA, such as the USA and Europe, and therapy could also become the treatment of choice. According to the pivotal study, a dose of 100 units of incobotulinumtoxinA, which is divided into the parotid and submandibular glands, is recommended. RimabotulinumtoxinB is approved in the USA only. To define the value of this therapy, we must consider anatomy, physiology, and available therapies. Therapy includes conservative measures such as functional dysphagia therapy, oral or transdermal application of anticholinergics, and, in selected cases, radiotherapy and surgical procedures. A combination of different approaches is optional. On the basis of the evidence and clinical experience, BoNT injections will be the first line of pharmacotherapy for chronic sialorrhea.

Long-term incobotulinumtoxinA treatment for chronic sialorrhea: Efficacy and safety over 64 weeks

BACKGROUND

Botulinum neurotoxin (BoNT) is an effective treatment for chronic sialorrhea; however, reliable and robust evidence supporting long-term efficacy and safety is lacking. This study investigated the efficacy and safety of repeated incobotulinumtoxinA injections for chronic sialorrhea over 64 weeks.

METHODS

Adults with sialorrhea were randomized (2:2:1) to incobotulinumtoxinA 75 U, incobotulinumtoxinA 100 U (n = 74 each), or placebo (n = 36) in the double-blind, placebo-controlled main period (NCT02091739). Eligible subjects entered the extension period and received dose-blinded incobotulinumtoxinA 75 or 100 U in three further 16±2-week injection cycles. Efficacy and safety assessments in subjects who received incobotulinumtoxinA throughout the study included unstimulated salivary flow rate (uSFR), subjects' Global Impression of Change Scale (GICS), Drooling Severity and Frequency Scale (DSFS), modified Radboud Oral Motor Inventory for Parkinson's Disease (mROMP) drooling, speech, and swallowing symptom scores, and incidence of adverse events (AEs).

RESULTS

In total, 173/184 subjects (94%) completed the main period and entered the extension period; 141 subjects received incobotulinumtoxinA 75 U (n = 69) or 100 U (n = 72) in both periods. Mean uSFR decreased consistently with repeated incobotulinumtoxinA 75 and 100 U treatment and by -0.16 and -0.17, respectively, at the end-of-study visit. Subjects' GICS, DSFS, and mROMP drooling scores also improved at all assessments. mROMP speech and swallowing scores remained stable. The most common treatment-related AEs during the extension period were dry mouth (4.4% and 11.1%) and dysphagia (1.5% and 4.2%).

CONCLUSIONS

Data support long-term efficacy and safety of repeated incobotulinumtoxinA treatment for sialorrhea, with no additional safety concerns reported over 64 weeks.

Botulinum Toxin A for Sialorrhoea Associated with Neurological Disorders: Evaluation of the Relationship between Effect of Treatment and the Number of Glands Treated

Background: Sialorrhoea and drooling are disabling manifestations of different neurological disorders. The aim of this study was to evaluate the effects of botulinum neurotoxin type A (BoNT/A) injection on hypersalivation in 90 patients with neurological diseases of different aetiologies, and to define the minimum number of injected salivary glands to reduce sialorrhoea. Determining the minimum number of glands that need to be engaged in order to have a significant reduction in drooling may be very useful for establishing the minimum total dosage of BoNT/A that may be considered effective in the treatment of hypersalivation. Methods: Twenty-five mouse units (MU) of BoNT/A (onabotulinumtoxin A, Botox; Allergan, Irvine, CA, USA; 100 MU/2 mL, 0.9% saline; or incobotulinumtoxin A, Xeomin; Merz Pharma, Germany; 100 MU/2 mL, 0.9% saline) were percutaneously injected into the parotid (p) glands and/or submandibular (s) glands under ultrasound control. On this basis, patients were divided into three groups. In group A (30 patients), BoNT/A injections were performed into four glands; in group B (30 patients), into three glands, and in group C (30 patients), into two glands. Patients treated in three glands (group B) were divided into two subgroups based on the treated glands (2 p + 1 s = 15 patients; 2 s + 1 p = 15 patients). Similarly, patients being injected in two glands (group C) were subdivided into three groups (2 p = 10 patients; 1 p + 1 s = 10 patients; 2 s = 10 patients). In patients who were injected in three and two salivary glands, saline solution was injected into the remaining one and two glands, respectively. Assessments were performed at baseline and at 2 weeks after the injections. Results: BoNT/A significantly reduced sialorrhoea in 82 out of 90 patients. The effect was more evident in patients who had four glands injected than when three or two glands were injected. The injections into three glands were more effective than injections into two glands. Conclusions: Our results have shown that BoNT/A injections induced a significant reduction in sialorrhoea in most patients (91%). In addition, we demonstrated that sialorrhoea associated with different neurological diseases was better controlled when the number of treated glands was higher.