Botulinum neurotoxin formulations: overcoming the confusion

The Effect of Climate on the Dose Requirements of Botulinum Toxin A in Cosmetic Interventions

BACKGROUND

Botulinum toxin A to the glabella is a popular cosmetic intervention. Functional musculature differences may arise from chronic behavioral adjustment to high sun exposure levels, requiring greater doses. This could affect clinical practice globally. This study investigated the effect of climate on real-world doses.

METHODS

The authors conducted a comparative cohort study using data from a registry from a single provider practicing across two centers: the United Kingdom and Malta. They classified one center as low sun exposure (United Kingdom winter month treatment) and the other as high sun exposure (Malta summer months). Patients were followed up once every 3 weeks and received top-up doses until full clinical paralysis was achieved. To standardize the comparison, the study included only women aged 35 to 60 years undergoing glabellar botulinum toxin treatment by experienced clinicians following standard procedures from 2012 to 2019. Smokers, those not seeking maximal paralysis, those documented as not compliant with posttreatment advice, those with colds or fevers, and those with broken cold supply chains were excluded. Univariable and multivariable analyses were undertaken.

RESULTS

A total of 523 patients were included: 292 "high-sun" patients and 231 "low-sun" patients. Mean total doses were significantly higher in the high-sun group (29.2 units versus 27.3 units; P = 0.0031). When correcting for age in multivariable analysis, the low-sun group still had lower total dose requirements ( P = 0.00574).

CONCLUSION

Patients injected with glabellar botulinum toxin in high-sun climates may have significantly increased dose requirements to achieve maximal paralysis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Real-world Implications of Botulinum Neurotoxin A Immunoresistance for Consumers and Aesthetic Practitioners: Insights from ASCEND Multidisciplinary Panel

Background

As long-term, regular aesthetic botulinum neurotoxin A (BoNT-A) use becomes more commonplace, it is vital to understand real-world risk factors and impact of BoNT-A immunoresistance. The first Aesthetic Council on Ethical Use of Neurotoxin Delivery panel discussed issues relating to BoNT-A immunoresistance from the health care professionals' (HCPs') perspective. Understanding the implications of BoNT-A immunoresistance from the aesthetic patient's viewpoint allows HCPs to better support patients throughout their aesthetic treatment journey.

Methods

A real-world consumer study surveyed 363 experienced aesthetic BoNT-A recipients across six Asia-Pacific territories. The survey mapped participants' BoNT-A aesthetic treatment journey and characterized awareness and attitudes relating to BoNT-A immunoresistance and treatment implications. At the second Aesthetic Council on Ethical use of Neurotoxin Delivery meeting, panelists discussed survey findings and developed consensus statements relating to the impact of BoNT-A immunoresistance on the aesthetic treatment journey.

Results

Aesthetic BoNT-A patients' depth of knowledge about BoNT-A immunoresistance remains low, and risk/benefit communications need to be more lay-friendly. The initial consultation is the most important touchpoint for HCPs to raise awareness of BoNT-A immunoresistance as a potential side effect considering increased risk with repeated high-dose treatments. HCPs should be cognizant of differences across BoNT-A formulations due to the presence of certain excipients and pharmacologically unnecessary components that can increase immunogenicity. Standardized screening for clinical signs of secondary nonresponse and a framework for diagnosing and managing immunoresistance-related secondary nonresponse were proposed.

Conclusion

These insights can help patients and HCPs make informed treatment decisions to achieve desired aesthetic outcomes while preserving future treatment options with BoNT-A.

Botulinum Toxin Injections for Psychiatric Disorders: A Systematic Review of the Clinical Trial Landscape

Botulinum toxin type A (BONT-A) has shown promise in improving the mood-related symptoms of psychiatric disorders by targeting muscles linked to the expression of negative emotions. We conducted a systematic review of past and ongoing efficacy trials of BONT-A therapy for psychiatric disorders to identify relevant trends in the field and discuss the refinement of therapeutic techniques. A comprehensive search for published clinical trials using BONT-A injections for psychiatric disorders was performed on 4 May 2023 through OVID databases (MEDLINE, Embase, APA PsycINFO). Unpublished clinical trials were searched through the ClinicalTrials.gov and International Clinical Trial Registry Platform public registries. The risk of bias was assessed using the JBI Critical Appraisal tools for use in systematic reviews. We identified 21 studies (17 published, 4 unpublished clinical trials) involving 471 patients. The studies focused on evaluating the efficacy of BONT-A for major depressive, borderline personality, social anxiety, and bipolar disorders. BONT-A was most commonly injected into the glabellar area, with an average dose ranging between 37.75 U and 44.5 U in published studies and between 32.7 U and 41.3 U in unpublished trials. The results indicated significant symptom reductions across all the studied psychiatric conditions, with mild adverse effects. Thus, BONT-A appears to be safe and well-tolerated for psychiatric disorders of negative affectivity. However, despite the clinical focus, there was a noted shortage of biomarker-related assessments. Future studies should focus on pursuing mechanistic explorations of BONT-A effects at the neurobiological level.

The Role of Botulinum Toxin Type-A in Spasticity: Research Trends from a Bibliometric Analysis

Botulinum toxin type-A (BoNT-A) has emerged as a key therapeutic agent for the management of spasticity. This paper presents a comprehensive bibliometric and visual analysis of research concerning BoNT-A treatment of spasticity to elucidate current trends and future directions in this research area. A search was conducted in the Web of Science database for articles focused on the use of BoNT-A in spasticity published between 2000 and 2022. We extracted various metrics, including counts of publications and contributions from different countries, institutions, authors, and journals. Analytical methods in CiteSpace were employed for the examination of co-citations, collaborations, and the co-occurrence of keywords. Our search yielded 1489 publications. Analysis revealed a consistent annual increase in research output. The United States, United Kingdom, and Italy were the leading contributors. The top institution in this research was Assistance Publique Hopitaux, Paris. The journal containing the highest number of relevant publications was Toxins. Key frequently occurring keywords were 'stroke', 'cerebral palsy', 'adult spasticity', and 'upper extremity'. This study identified 12 clusters of keywords and 15 clusters of co-cited references, indicating the main focus areas and emerging themes in this field. This study comprehensively analyzed and summarized trends in BoNT-A research in the field of spasticity over the past 22 years.

From Toxin to Treatment: A Narrative Review on the Use of Botulinum Toxin for Autonomic Dysfunction

Since its regulatory approval over a half-century ago, botulinum toxin has evolved from one of the most potent neurotoxins known to becoming routinely adopted in clinical practice. Botulinum toxin, a highly potent neurotoxin produced by Clostridium botulinum, can cause botulism illness, characterized by widespread muscle weakness due to inhibition of acetylcholine transmission at neuromuscular junctions. The observation of botulinum toxin's anticholinergic properties led to the investigation of its potential benefits for conditions with an underlying etiology of cholinergic transmission, including autonomic nervous system dysfunction. These conditions range from disorders of the integument to gastrointestinal and urinary systems. Several formulations of botulinum toxin have been developed and tested over time, significantly increasing the availability of this treatment for appropriate clinical use. Despite the accelerated and expanded use of botulinum toxin, there lacks an updated comprehensive review on its therapeutic use, particularly to treat autonomic dysfunction. This narrative review provides an overview of the effect of botulinum toxin in the treatment of autonomic dysfunction and summarizes the different formulations and dosages most widely studied, while highlighting reported outcomes and the occurrence of any adverse events.

Pain Control during the Treatment of Primary Palmar Hyperhidrosis with Botulinum Toxin A by a Topical Application of Liposomal Lidocaine: Clinical Effectiveness

Primary palmar hyperhidrosis (PPH) constitutes a debilitating condition that profoundly impacts the social, functional, and occupational aspects of individuals. The intradermal administration of botulinum toxin type A (BoNT-A) stands as an established therapeutic approach for PPH, albeit one frequently accompanied by considerable pain, posing challenges for patient tolerance. Our study aimed to assess the efficacy of combining cryoanalgesia spray (CA) with topical anesthesia utilizing a cream containing liposomal lidocaine at a concentration of 40 mg/g, with the objective of mitigating the pain associated with intradermal BoNT-A injection for PPH treatment. Nineteen participants, aged ≥18 years and afflicted with severe PPH, were enrolled in a double-blind randomized vehicle-controlled trial. Patient-perceived pain during the procedure was quantified using the Numeric Rating Scale (NRS). Statistical analysis was applied to the collected data. The combination of CA and the topical application of liposomal lidocaine during BoNT-A treatment for PPH resulted in diminished pain compared to CA alone and the combination of CA with the application of a basic cream. Topical anesthesia through the application of a liposomal lidocaine-containing cream emerged as a facile, secure, and efficacious approach for alleviating the pain associated with intradermal BoNT-A injection in PPH treatment. Furthermore, it demonstrated compatibility with CA, thereby offering a comprehensive strategy for pain management during BoNT-A administration.

Improvement in Quality-of-Life-Related Outcomes Following Treatment with IncobotulinumtoxinA in Adults with Limb Spasticity: A Pooled Analysis

A strong correlation has been reported between patient-reported quality of life (QoL) and the investigator-rated Disability Assessment Scale (DAS) in patients with spasticity. The current analysis evaluates the effect of incobotulinumtoxinA on QoL-related outcomes (limb position abnormality, as well as dressing- and hygiene-related disability, measured with the DAS) in adults with upper limb spasticity, using pooled data from six studies. Separate analyses for each DAS domain were performed using data from patients with disabilities for that domain (DAS score ≥1). Results showed that a significantly greater proportion of incobotulinumtoxinA-treated compared with placebo-treated patients achieved a ≥1-point reduction from baseline in each of the DAS domains (improvement) 4 weeks after the first injection. The benefits of incobotulinumtoxinA were observed regardless of the baseline severity of DAS impairment and of the time elapsed since stroke. The effects of incobotulinumtoxinA 4 weeks after injection were maintained or enhanced over multiple injection cycles for all three DAS domains, supporting the use of repeated injection cycles to provide sustained QoL benefit. IncobotulinumtoxinA represents an important treatment option to achieve better QoL-related outcomes for patients with upper limb spasticity, irrespective of the duration of their condition.

Crocodile tear syndrome treated with lacrimal gland incobotulinum toxin A injection: a report of two cases

Crocodile tear syndrome (CTS) is a late complication of facial nerve palsy characterized by unilateral lacrimation in response to gustatory stimulation. We present 2 cases of patients diagnosed with CTS after recovering from unilateral idiopathic facial nerve palsy. Both patients underwent transconjunctival lacrimal gland incobotulinumtoxinA injection, with doses of 5-16 units. The patients were seen in clinic for post-treatment follow-up at 2 weeks, 3 months, and 6 months. Outcomes were measured by treatment efficacy and adverse drug effects. Following treatment, both patients reported resolution of gustatory lacrimation. The patient treated with 16 U experienced transient ptosis and diplopia following injection, whereas the patient treated with 5-7.5 U experienced no adverse effects.

Biochemical Stability and Microbial Control of Reconstituted DaxibotulinumtoxinA-lanm for Injection

DaxibotulinumtoxinA-lanm for injection (DAXI) is a unique US Food and Drug Administration-approved product comprising daxibotulinumtoxinA and a stabilizing excipient peptide (RTP004). DAXI has a longer-labeled shelf life (72 h) following reconstitution than other botulinum toxin type A products. Here, we report the stability and microbial control of reconstituted DAXI when stored at 2 °C-8 °C over a period of 36 days (Study 1) and 7 days (Study 2) following reconstitution with unpreserved or preserved saline. The pH and biological activity of reconstituted DAXI in the 50 U/vial and 100 U/vial formats remained stable at the final assessed time point in both preserved and unpreserved saline when refrigerated (2 °C-8 °C). No changes in recoverable 150 kDa neurotoxin (measured by enzyme-linked immunosorbent assay) were observed over 6 days of refrigeration. Bacterial growth or pathogen proliferation was not observed in DAXI reconstituted in preserved or unpreserved saline in both studies.

Guidelines for the Use of Botulinum Toxin in Otolaryngology From the Korean Society of Laryngology, Phoniatrics and Logopedics Guideline Task Force

The Korean Society of Laryngology, Phoniatrics and Logopedics created a task force to establish clinical practice guidelines for the use of botulinum toxin (BT) in otolaryngology. We selected 10 disease categories: spasmodic dysphonia, essential vocal tremor, vocal fold granuloma, bilateral vocal fold paralysis, Frey's syndrome, sialocele, sialorrhea, cricopharyngeal dysfunction, chronic sialadenitis, and first bite syndrome. To retrieve all relevant papers, we searched the CORE databases with predefined search strategies, including Medline (PubMed), Embase, the Cochrane Library, and KoreaMed. The committee reported 13 final recommendations with detailed evidence profiles. The guidelines are primarily aimed at all clinicians applying BT to the head and neck area. In addition, the guidelines aim to promote an improved understanding of the safe and effective use of BT by policymakers and counselors, as well as in patients scheduled to receive BT injections.

Tailored Indications for Different Neurotoxins

Background

Minimally invasive procedures have become increasingly popular because they require minimal downtime and are effective for achieving a more youthful appearance. All U.S. Food and Drug Administration-approved neurotoxins are indicated for achieving similar effects, even though they are different in regard to structure, manufacturing technique, and storage requirements. It is agreed upon that each neurotoxin is unique and therefore not interchangeable. The aim of the author is to provide an approach for choosing the optimal toxin in different indications regarding the area of treatment, the age and characteristics of the patient, potential risks, and ultimate goals.

Methods

As the country that the author practices carries onabotulinum (ONA), prabotulinum (PRA), and abobotulinum (ABO) toxin type-A, one of these three toxins was preferred for each category. ABO toxins were preferred in wide areas due to the broader action halo. Typical examples include hyperhidrosis treatment, wide forehead area, and calf slimming. In areas where very precise and targeted treatment is required, PRA and ONA toxins were preferred to limit potential side effects due to wider diffusion. First-time patients were typically treated with PRA toxins for a softer trial periods where as "repeat" patients were successfully treated with ABO toxins.

Results

No toxin is superior to the other in terms of producing effects. Yet, small differences in their properties can allow the plastic surgeon to cater to each patient's needs while yielding the most optimal results.

Conclusions

This study is meant to serve as a guideline for choosing the ideal toxin in different patient settings and indications.

Consensus Statement on the Use of Botulinum Neurotoxin in the Middle East

Background

Aesthetic minimally invasive procedures have become very popular and culturally acceptable among Middle Eastern populations. Botulinum neurotoxin type A (BoNTA) is a valuable treatment modality for many cosmetic as well as therapeutic indications. The presence of BoNTA in our toolkit has revolutionized the field of aesthetic medicine to the point where it is now one of the most commonly performed cosmetic procedures worldwide. This consensus considers popular on- and off-label BoNTA indications in the Middle East.

Methods

A multinational group of ten key opinion leaders, experts in facial plastic surgery and dermatology, convened the Middle East Aesthetics Consensus Group and reviewed the aesthetic applications of BoNTA. Recommendations and position statements were drafted based on the integration of the panel's clinical experience with published data, targeted to the practices implemented in the Middle Eastern and the global population.

Results

Guidance statements are presented covering Middle Eastern facial characteristics and beauty ideals, BoNTA characteristics, pre-operative counselling, treatment indications and anatomical considerations, off-label and special uses including high-dose recommendations, and post-treatment advice. Throughout, an evidence-based approach to selection of products and injection techniques is provided, supplemented by the experts' advice on injections dosages and placement.

Conclusion

This consensus reflects the knowledge and expertise of physicians practicing in the Middle East. The panel acknowledged the use of on-label indications and variability in the toxin formulations and immunogenicity and agreed upon a wide use of "off-label" indications.

SAMCEP Society consensus on the treatment of upper facial lines with botulinum neurotoxin type A: A tailored approach

BACKGROUND

The safety and efficacy of botulinum neurotoxin type A (BoNTA) treatments are well established, but injection techniques, target muscles, and toxin doses continue to evolve, with each refinement producing improvements in treatment outcomes. The recommendations in this consensus move away from standard templates and illustrate how to tailor treatments to individual patterns and strengths of muscle activity, and patient preferences.

METHODS

Seventeen experts in the fields of plastic surgery, dermatology, ophthalmology, otorhinolaryngology, and neurology convened in 2022 to develop consensus-based recommendations for the use of botulinum toxin A for the treatment of horizontal forehead lines, glabellar frown lines, and crow's feet lines that reflect current clinical practice. The focus was on how to tailor injections to individual patients to optimize treatment outcomes.

RESULTS

For each upper face indication, consensus members describe how to perform a dynamic assessment to optimize the dose and injection technique for each patient. A tailored treatment protocol is presented for commonly observed patterns of dynamic lines. Units of Inco are defined and the precise location of injection points, illustrated with the use of anatomical images.

CONCLUSION

This consensus provides up-to-date recommendations on the tailored treatment of upper facial lines based on the latest research and collective clinical experience of the expert injectors. Optimal outcomes require thorough patient evaluation, both at rest and during animation, using both visual and tactile cues; detailed understanding of facial muscular anatomy and how opposing muscles interact; and use of a BoNTA with high precision to target identified zones of excess muscle activity.

Complications of toxins and fillers in facial aesthetics

Dermal filler and botulinum toxin injections are among the most performed non-invasive procedures for rejuvenation and contouring, internationally. Although most dermal fillers and approved botulinum toxins are well tolerated with a high safety profile, adverse events and/or complications can happen. Injection-related sequelae and side effects are usually rare, mild, transient, and self-limiting in nature. However, devastating and life-changing complications, such as intravascular occlusion, skin necrosis, permanent visual impairment, and stroke, have been reported. Risk reduction measures include an in-depth knowledge of anatomy, physiology, and pharmacology, correct patient selection, correct identification of clinical indications, and, fundamentally, the importance of appropriate skill and training. In this paper, some of the complications are discussed and advice on how to minimise adverse events and complications from these injectables is provided.

Office-based facial plastics procedures: Neuromodulators

Botulinum toxin is a potent neuromodulator commonly used for cosmetic applications in the clinic. In this article, we reviewed the various formulations of botulinum toxin type A commercially available in the United States, as well as clinical pearls for preprocedural planning, common in-office injections, and management of complications.

Cancer Pain Management: A Narrative Review of Current Concepts, Strategies, and Techniques

Pain is frequently reported during cancer disease, and it still remains poorly controlled in 40% of patients. Recent developments in oncology have helped to better control pain. Targeted treatments may cure cancer disease and significantly increase survival. Therefore, a novel population of patients (cancer survivors) has emerged, also enduring chronic pain (27.6% moderate to severe pain). The present review discusses the different options currently available to manage pain in (former) cancer patients in light of progress made in the last decade. Major progress in the field includes the recent development of a chronic cancer pain taxonomy now included in the International Classification of Diseases (ICD-11) and the update of the WHO analgesic ladder. Until recently, cancer pain management has mostly relied on pharmacotherapy, with opioids being considered as the mainstay. The opioids crisis has prompted the reassessment of opioids use in cancer patients and survivors. This review focuses on the current utilization of opioids, the neuropathic pain component often neglected, and the techniques and non-pharmacological strategies available which help to personalize patient treatment. Cancer pain management is now closer to the management of chronic non-cancer pain, i.e., "an integrative and supportive pain care" aiming to improve patient's quality of life.

Addressing the Real-World Challenges of Immunoresistance to Botulinum Neurotoxin A in Aesthetic Practice: Insights and Recommendations from a Panel Discussion in Hong Kong

With increasing off-label aesthetic indications using higher botulinum neurotoxin A (BoNT-A) doses and individuals starting treatment at a younger age, particularly in Asia, there is a greater risk of developing immunoresistance to BoNT-A. This warrants more in-depth discussions by aesthetic practitioners to inform patients and guide shared decision-making. A panel comprising international experts and experienced aesthetic practitioners in Hong Kong discussed the implications and impact of immunoresistance to BoNT-A in contemporary aesthetic practice, along with practical strategies for risk management. Following discussions on a clinical case example and the results of an Asia-Pacific consumer study, the panel concurred that it is a priority to raise awareness of the possibility and long-term implications of secondary non-response due to immunoresistance to BoNT-A. Where efficacy and safety are comparable, a formulation with the lowest immunogenicity is preferred. The panel also strongly favored a thorough initial consultation to establish the patient's treatment history, explain treatment side effects, including the causes and consequences of immunoresistance, and discuss treatment goals. Patients look to aesthetic practitioners for guidance, placing an important responsibility on practitioners to adopt risk-mitigating strategies and adequately communicate important risks to patients to support informed and prudent BoNT-A treatment decisions.

Replacement of the Mouse LD50 Assay for Determination of the Potency of AbobotulinumtoxinA with a Cell-Based Method in Both Powder and Liquid Formulations

Botulinum neurotoxins (BoNTs) are important therapeutic agents. The in vivo median lethal dose (LD₅₀) assay has been commonly used to measure the potency of BoNT commercial preparations. As an alternative, we developed cell-based assays for abobotulinumtoxinA in both powder (Dysport^®, Azzalure^®) and liquid (Alluzience^®) formulations using the in vitro BoCell^® system. The assays demonstrated linearity over 50-130% of the expected relative potency, with a correlation coefficient of 0.98. Mean recoveries of 90-108% of the stated potency were observed over this range. The coefficients of variation for powder and liquid formulations, respectively, were 3.6% and 4.0% for repeatability and 8.3% and 5.0% for intermediate precision. A statistically powered comparability assessment of the BoCell^® and LD₅₀ assays was performed. Equivalence was demonstrated between the assays for the liquid formulation at release and end of shelf life using a paired equivalence test with predefined equivalence margins. For the powder formulation, the assays were also shown to be equivalent for release samples and when determining loss of potency following thermal degradation. The BoCell^® assay was approved for establishing the potency of abobotulinumtoxinA for both powder and liquid formulations in Europe and for the powder formulation only in the USA.

Current Insights into the Formulation and Delivery of Therapeutic and Cosmeceutical Agents for Aging Skin

“Successful aging” counters the traditional idea of aging as a disease and is increasingly equated with minimizing age signs on the skin, face, and body. From this stems the interest in preventative aesthetic dermatology that might help with the healthy aging of skin, help treat or prevent certain cutaneous disorders, such as skin cancer, and help delay skin aging by combining local and systemic methods of therapy, instrumental devices, and invasive procedures. This review will discuss the main mechanisms of skin aging and the potential mechanisms of action for commercial products already on the market, highlighting the issues related to the permeation of the skin from different classes of compounds, the site of action, and the techniques employed to overcome aging. The purpose is to give an overall perspective on the main challenges in formulation development, especially nanoparticle formulations, which aims to defeat or slow down skin aging, and to highlight new market segments, such as matrikines and matrikine-like peptides. In conclusion, by applying enabling technologies such as those delivery systems outlined here, existing agents can be repurposed or fine-tuned, and traditional but unproven treatments can be optimized for efficacious dosing and safety.

The safety of botulinum neurotoxin type A's intraarticular application in experimental animals

In vivo studies of botulinum neurotoxin type A (BoNT-A) enabled characterization of its activity in the nociceptive sensory system separate from its preferred action in motor and autonomic nerve terminals. However, in the recent rodent studies of arthritic pain which employed high intra-articular (i.a.) doses (expressed as a total number of units (U) per animal or U/kg), possible systemic effects have not been conclusively excluded. Herein we assessed the effect of two pharmaceutical preparations, abobotulinumtoxinA (aboBoNT-A, 10, 20, and 40 U/kg corresponding to 0.05, 0.11, and 0.22 ng/kg neurotoxin) and onabotulinumtoxinA (onaBoNT-A, 10 and 20 U/kg corresponding to 0.09 and 0.18 ng/kg, respectively) injected into the rat knee, on safety-relevant readouts: digit abduction, motor performance and weight gain during 14 days post-treatment. The i. a. toxin produced dose-dependent impairment of the toe spreading reflex and rotarod performance, which was moderate and transient after 10 U/kg onaBoNT-A and ≤20 U/kg aboBoNT-A doses, and severe and long-lasting (examined up to 14 days) after ≥20 U/kg of onaBoNT-A and 40 U/kg aboBoNT-A. In addition, lower toxin doses prevented the normal weight gain compared to controls, while higher doses induced marked weight loss (≥20 U/kg of onaBoNT-A and 40 U/kg aboBoNT-A). Commonly employed BoNT-A formulations, depending on the doses, cause local relaxation of the surrounding muscles and systemic adverse effects in rats. Thus, to evade possible toxin unwanted local or systemic spread, careful dosing and motor testing should be mandatory in preclinical behavioral studies, irrespective of the sites and doses of toxin application.

The use of botulinum toxin in the acute management of symptomatic complex incisional hernia: a case series

PURPOSE

Complications of incisional hernia are amongst the commonest presentations to the emergency surgical take. Outcomes from emergency hernia repair are poor, particularly for those with complex defects and for the growing population of comorbid, high-risk patients. Attempts to avoid emergency surgery by improving success rates of non-operative management could prove hugely beneficial. Botulinum toxin A (Botox) is already used in the elective management of incisional hernia and this study evaluates if the relaxation produced could be used to augment the outcomes of conservative management of acutely presenting incisional hernia.

METHODS

Patients presenting between October 2020 and April 2022 without evidence of visceral ischaemia, who had been selected for a non-operative approach, were given 300 units of Botox under image guidance to the abdominal wall in addition to standard conservative measures.

RESULTS

Twelve patients were eligible for Botox administration. Median age was 75 years and median BMI was 36.45 kg/m². All patients were high risk; minimum ASA score was 3, and median frailty score was 5. In ten patients, symptoms resolved following Botox allowing for discharge without further complication. Seven subsequently referred on to the abdominal wall team. Symptoms did not settle in the two remaining patients; one required emergency laparotomy and the second was palliated.

CONCLUSION

Botox may be a useful adjunct to established non-operative measures in patients with acute presentations of incisional hernia. It may improve the acute symptoms, eliminate the need for high-risk emergency surgery, or provide a bridge to abdominal wall reconstruction.

A Preclinical Study Comparing the Activity and Potency of OnabotulinumtoxinA and PrabotulinumtoxinA

Objective

The goal of this study was to compare the unit-to-unit biological activity of the vacuum-dried formulation of prabotulinumtoxinA (prabotA) and onabotulinumtoxinA (onabotA) in preclinical assays.

Methods

Reconstituted 100 U vials of prabotA and onabotA were tested in 3 distinct assays: plate-capture light chain activity (PC-LCA), measuringlight chain enzymatic activity after recovery of toxin from reconstituted product using a proprietary toxin capture step; cell-based potency assay (CBPA), measuring the intoxication steps of binding, translocation, and light chain activity (synaptosomal-associated protein 25 [SNAP25] cleavage); and mouse Digit Abduction Score (DAS), evaluating muscle paresis. Each assay tested 3 separate prabotA and onabotA lots on several independent test dates.

Results

Multiple orthogonal assays established that when assessed on a unit-to-unit basis, the biological activity of prabotA is lower than that of onabotA. In the PC-LCA and CBPA assays, onabotA displayed 1.51 ± 0.14-fold higher (mean ± SD) and 1.33 ± 0.07-fold higher (mean of pooled lots ± SEM) activity than prabotA, respectively. Similarly, the mouse DAS data showed that onabotA had 1.4 ± 0.1-fold higher (mean ± SEM) potency than prabotA. Results of all 3 assays demonstrated differences in potency, efficacy, and duration of action between onabotA and prabotA on a unit-to-unit basis.

Conclusion

Preclinical assays established differences in the biological activity of onabotA and prabotA, supporting that the units of biological activity are not interchangeable.

Sensory Symptoms Associated with Aesthetic Botulinum Toxin A Treatments

A retrospective review of patients who switched from onabotulinumtoxinA (onaA) and/or abobotulinumtoxinA (aboA) to incobotulinumtoxinA (incoA) found anecdotal reports of differences in "feel," including a "lighter" feel or treatment-associated tightness. We surveyed the frequency of these sensations as an initial proof of concept of toxin proprioception among our patients who switched toxins.

METHODS

Seventy-nine patients who had past facial aesthetic treatments with more than one botulinum toxin A (BoNT/A) formulation completed a questionnaire on their experience of treatment-associated sensations, including stiffness or a frozen feeling.

RESULTS

Treatment-associated sensations of tightness (47.3%), headache (41.8%), heaviness (38.2%), feeling frozen (29.1%), stiffness (20.0%), and weakness (20.0%) were reported by 55 of 79 patients. Furthermore, 78.2% of 55 patients noted an interformulation sensory difference. Of 79 patients surveyed, 68.4% of onaA-treated patients associated sensations with onaA, 39.1% of aboA-treated patients associated sensations with aboA, and 12.2% of incoA-treated patients associated sensations with incoA.

CONCLUSIONS

Some patients reported a different feel between toxins, and the difference in frequency of treatment-associated sensation varies between the different formulations used. Given the fine coordination of facial expressive muscles, we suspect that associated proprioceptive afferents are involved. Our findings confirm that post-toxin treatment-associated sensations can be detected by some patients, and this is likely due to the variations between the formulations. Failing to advise patients of this before switching formulations may cause a misperception that the treatment is not working well or that its effect has worn off prematurely, and some patients may consider switching formulations to reduce these conscious proprioceptive sensations.

Voice Tremor and Botulinum Neurotoxin Therapy: A Contemporary Review

Voice tremor is a common, yet debilitating symptom for patients suffering from a number of tremor-associated disorders. The key to targeting effective treatments for voice tremor requires a fundamental understanding of the pathophysiology that underpins the tremor mechanism and accurate identification of the disease in affected patients. An updated review of the literature detailing the current understanding of voice tremor (with or without essential tremor), its accurate diagnosis and targeted treatment options was conducted, with a specific focus on the role of botulinum neurotoxin. Judicious patient selection, following detailed characterisation of voice tremor qualities, is essential to optimising treatment outcomes for botulinum neurotoxin therapy, as well as other targeted therapies. Further focused investigation is required to characterise the response to targeted treatment in voice tremor patients and to guide the development of innovative treatment options.

Botulinum toxin A in dentistry and orofacial surgery: an evidence-based review - part 2: cosmetic applications

Objective An evidence-based review on the role of botulinum toxin type A (BoNTA) on diverse cosmetic applications of interest to dental practitioners and allied specialities. In this context, to identify the cosmetic treatments that have an evidence-based rationale against areas requiring further research, with a view to assess the safety and efficacy of BoNTA.Data source and selection A comprehensive search was conducted using Cochrane Library of Systematic Reviews, Cochrane Central Register of Controlled Trials, and PubMed (Medline) electronic databases. Thirty-nine studies of variable quality were included. The Best Evidence Topics (BETs) Critical Appraisal Tool was used to facilitate the quality assessment of relevant studies.Data extraction Based on current level II evidence, BoNTA was safe and effective to improve facial contour, reduce volume and thickness of bilateral hypertrophic masseter. Conservative doses using a combined approach of BoNTA and hyaluronic acid was recommended as a safe and effective treatment for perioral enhancement supported by level II evidence. There was limited evidence, not higher than level III, to support BoNTA effectiveness for gummy smile associated to perioral musculature hyperactivity, while jawline sculpting targeting the platysma muscle had lower level IV evidence up to this date.Conclusion BoNTA has been widely used off-label for the investigated cosmetic orofacial conditions, with reports of 'good patient and practitioner satisfaction'. However, there is limited high-quality evidence to support the long-term safety and effectiveness of repetitive BoNTA injections. Additionally, no studies were found that provided a cost-effectiveness evaluation of BoNTA formulations against other current cosmetic interventions. Well-designed clinical trials, including long-term follow-up, would help to provide robust evidence-based recommendations for clinical practice, supporting BoNTA popularity, independently or in a combined approach.

Causes of Botulinum Toxin Treatment Failure

Purpose

The purpose of this article is to review the cause of botulinum toxin (BT) failure and determine the ways to minimize the risks of its occurrence.

Methods

A PubMed and Google Scholar literature search was conducted with the search terms botulinum toxin, treatment, failure, causes, and prevention. Fifteen relevant articles were found and used as the scientific base for this article.

Results

The failure of BT therapy is associated with immunogenic and non-immunogenic causes and the formation of neutralizing antibodies toward the active components of BT or the complexing proteins. Enzyme-linked immunosorbent assay (ELISA) testing and mouse hemidiaphragm assay (MHA) can diagnose the failure. The risk of developing treatment failure can be minimized by using complexing protein-free formulations, selecting a treatment regimen with the least immunogenicity, proper injection technique, and gentle product handling.

Conclusion

The treatment failure can compromise the success of BT treatment. Current medical literature shows controversial evidence for and against BT immunogenicity. Therefore, the cause of BT failure is likely to be multifactorial.

THE PHARMACOLOGICAL TREATMENT AND MANAGEMENT OF HYPERHIDROSIS

INTRODUCTION

Idiopathichyperhidrosis is a dysfunctional disorder involving eccrine sweat glands and its impact on patients' daily quality of life is well-known. Unlike some years ago, when only poor effective and safe therapeutic alternatives were available, nowadays, several emerging pharmacological active substances have gained significant space as treatment options.

AREAS COVERED

The authors report on, in this narrative review, the emerging data from the literature focusing on the pharmacological treatments to draw up a drug treatments flow-chart for patients with idiopathic hyperhidrosis, taking into consideration specific differences among axillary, palmoplantar and craniofacial hyperhidrosis.

EXPERT OPINION

Idiopathic hyperhidrosis, regardless of the site of involvement, remains a functional disorder that places a significant burden on patients. After balancing efficacy against adverse events, systemic therapy, although off-label for all forms of hyperhidrosis can represent an additive therapeutic option for patients with insufficient response to topical treatment according to a step wise therapeutic approach. Until the pathophysiological mechanisms underlying hyperhidrosis are clear, and the etiological therapeutic approach become realistic, the greatest challenge in the therapeutic management of hyperhidrotic patients seems to be the search for the most convenient combination between different therapeutic modalities (topical and systemic agents, and botulinum toxins) to achieve long-term control of the disease symptoms.

Emerging Trends in Botulinum Neurotoxin A Resistance: An International Multidisciplinary Review and Consensus

Botulinum neurotoxin A (BoNT-A) injection is the most widely performed aesthetic procedure and a first-line therapeutic option for various medical conditions. The potential for BoNT-A immunoresistance and secondary nonresponse related to neutralizing antibody (NAb) formation warrants attention as the range of BoNT-A aesthetic applications continues to expand.

Methods

An international multidisciplinary panel reviewed published evidence on BoNT-A immunoresistance in aesthetic and therapeutic applications and discussed best practices integrating clinical, ethical, and aesthetic considerations. Consensus statements relating to awareness, assessment, and management of the risk of NAb-related secondary nonresponse in aesthetic practice were developed.

Results

There was a consensus that, as doses used in aesthetic practice become like those in therapeutics, rates of NAb formation may be expected to increase. However, the true extent of NAb formation in aesthetics is likely underestimated due to limitations of published evidence and variability in treatment patterns of aesthetic patients. Since BoNT-A therapy is often lifelong, practitioners need to recognize immunogenicity as a potential complication that might affect future therapeutic use and strive to minimize modifiable risk factors. The selection and use of a BoNT-A product with the least immunogenic potential from the beginning may thus be advantageous, especially when treatment with high doses is planned.

Conclusions

In view of current trends in BoNT-A aesthetic use, it is essential for practitioners to conduct thorough clinical assessments, inform patients of treatment risks, and develop BoNT-A treatment plans to minimize immunogenicity. This can help preserve the option of continued or future BoNT-A treatment with satisfactory outcomes.

Botulinum toxin A in dentistry and orofacial surgery: an evidence-based review - part 1: therapeutic applications

Objective An evidence-based review on the safety and efficacy of botulinum toxin type-A (BoNTA) in orofacial conditions, focusing on the therapeutic applications and role of BoNTA as an adjuvant treatment.Data source and selection Data was collected using PubMed (Medline), Cochrane Library of Systematic Reviews and Cochrane Central Register of Controlled Trials electronic databases. Having satisfied the search parameters, 32 studies for therapeutic applications and 26 for BoNTA as an adjunctive treatment were included. The quality of relevant studies was assessed using the Best Evidence Topics (BETs) Critical Appraisal Tool.Data extraction The highest level of evidence (LOE) behind BoNTA safety and efficacy was for wound healing and scar management in the orofacial surgery context, where BoNTA was presented as an adjunctive modality. Level-I evidence was controversial for temporomandibular disorders and bruxism. However, it showed promising results for painful temporomandibular disorders of myogenic origin refractory to conservative therapies, and to decrease muscle contraction intensity in sleeping bruxism. There was only one level-II study for persistent recurrent aphthous stomatitis. Data showed limited level-III evidence for orofacial pain conditions (temporomandibular joint recurrent dislocation and pain, burning mouth syndrome or atypical odontalgia), oral cancer complications, or as an adjuvant to maxillofacial and orthognathic surgeries. Benefits of BoNTA in prosthodontics had weak level-IV evidence. No evidence was found among the periodontology field.Conclusion There is growing evidence to support the safety and efficacy of BoNTA in the investigated orofacial pathological conditions, with high levels of satisfaction from the patient and clinician perspective. However, there are some inconsistencies and limited high-quality evidence available. Well-designed controlled clinical trials are necessary to evaluate long-term safety, efficacy and cost-effectiveness before BoNTA is widely adopted with irrefutable evidence-based clinical guidelines.

Comparative Pharmacodynamics of Three Different Botulinum Toxin Type A Preparations following Repeated Intramuscular Administration in Mice

Botulinum neurotoxin type A (BoNT/A) causes muscle paralysis by blocking cholinergic signaling at neuromuscular junctions and is widely used to temporarily correct spasticity-related disorders and deformities. The paralytic effects of BoNT/A are time-limited and require repeated injections at regular intervals to achieve long-term therapeutic benefits. Differences in the level and duration of effectivity among various BoNT/A products can be attributed to their unique manufacturing processes, formulation, and noninterchangeable potency units. Herein, we compared the pharmacodynamics of three BoNT/A formulations, i.e., Botox^® (onabotulinumtoxinA), Xeomin^® (incobotulinumtoxinA), and Coretox^®, following repeated intramuscular (IM) injections in mice. Three IM injections of BoNT/A formulations (12 U/kg per dose), 12-weeks apart, were administered at the right gastrocnemius. Local paresis and chemodenervation efficacy were evaluated over 36 weeks using the digit abduction score (DAS) and compound muscle action potential (CMAP), respectively. One week after administration, all three BoNT/A formulations induced peak DAS and maximal reduction of CMAP amplitudes. Among the three BoNT/A formulations, only Coretox^® afforded a significant increase in paretic effects and chemodenervation with a prolonged duration of action after repeated injections. These findings suggest that Coretox^® may offer a better overall therapeutic performance in clinical settings.

Therapeutic Approach to Botulinum Injections for Hemifacial Spasm, Synkinesis and Blepharospasm

The aim of this study was to show our therapeutic outcome of botulinum injection to the facial muscles and thereby to find the best therapeutic concept which should be embraced. The decision to treat the lower eyelid with 1-point or 2-points injection was randomly taken as there is no consensus regarding this debate. Injections of the lateral end of the upper eyelid were performed more laterally to the conventional injection point, just lateral to the conjunction of the upper and lower eyelids. Twenty-three patients (12 hemifacial spasm, 6 blepharospasm, 5 post facial palsy synkinesis) were enrolled. Data were retrieved from 112 visits between 2019 and 2022. Overall, 84.9% of the treatments had moderate or marked improvement. The most common side effect was facial weakness (11.8%). Neither ptosis nor diplopia were noted. Two-points regimen in the lower eyelid was associated with a lower risk of facial weakness (p = 0.01), compared to 1-point regimen, with a better therapeutic outcome as reflected by more favorable PGI-C scores (p = 0.04). Injection of the pretarsal segment of the upper eyelid, just onto or even lateral to the conjunction of the upper and lower eyelids, lowers the risk of ptosis.

Time to onset and duration of botulinum toxin efficacy in movement disorders

Background

Botulinum toxin (BoNT) is a valuable treatment in movement disorders; however, time to onset and duration of efficacy may widely differ among patients. We aimed to clarify the impact of main demographic and clinical features on time to onset and duration of BoNT efficacy.

Methods

We analyzed time-to-onset and duration of BoNT efficacy in 186 consecutive patients treated with BoNT for blepharospasm, cervical dystonia, facial hemispasm, oromandibular dystonia, limb dystonia, and sialorrhea due to Parkinsonism. The following factors were considered as potential efficacy predictors: doses and types of toxin, sex, age, years of treatment, and clinical condition. Kruskall–Wallis, Spearman correlation, and multivariate linear regression were used for statistical analysis.

Results

The average time to onset was 6.7 ± 5 days and duration of BONT efficacy 78.5 ± 28.4 days. Both time to onset and duration of efficacy were correlated with BoNT doses (p: 0.007 and p: 0.02). The multiple regression analysis showed that sex, age, years of BoNT treatment, doses, type of toxin, and clinical condition significantly predicted time to onset (F(11, 171) = 2.146, p: 0.020) with age being the strongest predictor (p: 0.004).

The same model explained 20.1% of the variance of duration of BoNT efficacy, showing a significant prediction of the outcome (F(11, 164) = 3.754, p < 0.001), with doses (p < 0.001), type of toxin (p: 0.017), and clinical condition (p < 0.001) being the strongest predictors.

Conclusion

Our findings suggest that age, type of toxin, clinical condition and especially doses may account for the variability of BoNT efficacy in terms of time to onset and duration.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-022-10995-2.

Incobotulinum toxin A with a one-year long-lasting effect for trapezius contouring and superior efficacy for the treatment of trapezius myalgia

Context:

Based on various Botulinum toxin A products, reports of the lower efficacy of Incobotulinum toxin A compared with Onabotulinum toxin A for muscle contouring were observed. In addition, complications of trapezius myalgia and shoulder contouring treatment from malpractice have been reported.

Aims:

The study aimed at comparing the efficacy between Incobotulinum toxin A and Onabotulinum toxin A; research was conducted on a safe treatment technique for trapezius hypertrophy and trapezius myalgia.

Materials and Methods:

A split-shoulder, double-blind, randomized controlled trial was performed. Twenty volunteers with trapezius hypertrophy and trapezius myalgia were randomly injected with 30 units of Incobotulinum toxin A and Onabotulinum toxin A in each trapezius muscle guided by ultrasound.

Results:

The trapezius thickness among those receiving treatment with Onabotulinum toxin A and Incobotulinum toxin A on day 60 was 7.35 ± 1.11 and 7.33 ± 1.21 mm, respectively, which did not portray a significant difference (P = 0.991). Compared with the muscle size from day 60 to one year, the size of the trapezius muscle that had been treated by Onabotulinum toxin type A regained a significantly larger size compared with that treated by Incobotulinum toxin A (P = 0.027). On comparing the size of the trapezius muscle treated by Incobotulinum toxin A between one year and day 0, it was observed that the trapezius thickness at one year had significantly decreased (P < 0.001). On comparing the pain score from day 60 to day 0, it was observed that the pain scores of trapezius myalgia treated by Onabotulinum toxin A and Incobotulinum toxin A significantly differed (P = 0.003).

Conclusions:

Incobotulinum toxin A had the same efficacy but a longer lasting effect for the trapezius size contouring and a higher efficacy for trapezius myalgia treatment compared with Onabotulinum toxin A.

Botulinum toxin in cancer therapy-current perspectives and limitations

Abstract

Different serotypes of botulinum toxins (BoNTs) act upon different types of SNARE proteins. This property is used in aesthetic medicine to treat certain eye disorders such as crossed eyes (strabismus) and uncontrolled blinking (blepharospasm), to treat muscle spasms or movement disorders, and, for the two last decades, more and more often, to provide support in cancer therapy, especially so as to obtain analgesic effects upon spastic conditions. The limited literature data also suggests that the addition of BoNTs to the culture of cancer cell lines reduces cell growth, and mitotic activity, and promotes their apoptosis. BoNTs have several advantages that can be emphasized: BoNTs act on both perfusion and oxygenation; moreover, BoNTs are considered to be safe and free of systemic side effects upon administration. Recently, advances in molecular biology techniques have allowed a wide variety of novel BoNT constructs with alternative functions. These constructs could be assessed as potential new classes of anti-cancer drugs. This creates new potential perspectives in the wider use of non-toxic modified BoNT constructs in cancer therapy. In the light of the mentioned premises and existing literature reports, the aim of this review is to summarize current data and reports considering BoNT use in cancer therapy.

Key points

•Botulinum toxin (BoNTs) may be useful in cancer treatment.

•Botulinum toxin can serve as an analgesic after cancer radiotherapy.

•Botulinum toxin has the ability to inhibit tumor growth and promote apoptosis of neoplastic cells.

Botulinum toxin type A injections for masticatory muscles hypertrophy: A systematic review

The aim of this study is to compare the efficacy of single-point injection of botulinum toxin A versus multi-point operative protocols found in the literature in reducing hypertrophy in patients with masticatory muscle hypertrophy. A systematic review was performed in accordance with the Park et al., 2018 guidelines, selecting articles from PubMed, Google Scholar, Web of Science and Ovid databases up to July 8, 2020.28 studies met the eligibility criteria. 748 patients were treated for masseter hypertrophy (MH) and 4 patients for temporal muscle hypertrophy. As for MH: in 45.2% of cases 3 injection sites (IS) were used, in 18.8% 1 IS, in 16.2% 2 IS, in 13% 5 IS, in 4.1% 6 IS, 2.7% 4 IS. At three months, the mean reduction in masseter muscle thickness is 26-31% when 1 IS was used, 28% in 2 IS, 12-27% in 3 IS and 22-30% in 6 IS. Heterogeneity of results, high bias level and selective reports led to a difficult efficacy comparison of the injection techniques described. Data suggest that the lowest number of IS possible should be used until stronger evidences are presented. Homogeneity in pre- and post-operative protocols is needed to establish a reliable setting for the condition under study.

A consensus statement on the use of botulinum toxin in pediatric patients

Botulinum toxin has been used in medicine for the past 30 years. However, there continues to be controversy about the appropriate uses and dosing, especially in the pediatric population. A panel of nine pediatric physiatrists from different regions and previous training programs in the United States were nominated based on institutional reputation and botulinum toxin (BoNT) experience. Based on a review of the current literature, the goal was to provide the rationale for recommendations on the administration of BoNT in the pediatric population. The goal was not only to review safety, dosing, and injection techniques but also to develop a consensus on the appropriate uses in the pediatric population. In addition to upper and lower limb spasticity, the consensus also provides recommendations for congenital muscular torticollis, cervical dystonia, sialorrhea, and brachial plexus palsies.

Use of Crystallography and Molecular Modeling for the Inhibition of the Botulinum Neurotoxin A Protease

Botulinum neurotoxins (BoNTs) are extremely toxic and have been deemed a Tier 1 potential bioterrorism agent. The most potent and persistent of the BoNTs is the "A" serotype, with strategies to counter its etiology focused on designing small-molecule inhibitors of its light chain (LC), a zinc-dependent metalloprotease. The successful structure-based drug design of inhibitors has been confounded as the LC is highly flexible with significant morphological changes occurring upon inhibitor binding. To achieve greater success, previous and new cocrystal structures were evaluated from the standpoint of inhibitor enantioselectivity and their effect on active-site morphology. Based upon these structural insights, we designed inhibitors that were predicted to take advantage of π-π stacking interactions present in a cryptic hydrophobic subpocket. Structure-activity relationships were defined, and X-ray crystal structures and docking models were examined to rationalize the observed potency differences between inhibitors.

Neurocosmetics in Skincare—The Fascinating World of Skin–Brain Connection: A Review to Explore Ingredients, Commercial Products for Skin Aging, and Cosmetic Regulation

The “modern” cosmetology industry is focusing on research devoted to discovering novel neurocosmetic functional ingredients that could improve the interactions between the skin and the nervous system. Many cosmetic companies have started to formulate neurocosmetic products that exhibit their activity on the cutaneous nervous system by affecting the skin’s neuromediators through different mechanisms of action. This review aims to clarify the definition of neurocosmetics, and to describe the features of some functional ingredients and products available on the market, with a look at the regulatory aspect. The attention is devoted to neurocosmetic ingredients for combating skin stress, explaining the stress pathways, which are also correlated with skin aging. “Neuro-relaxing” anti-aging ingredients derived from plant extracts and neurocosmetic strategies to combat inflammatory responses related to skin stress are presented. Afterwards, the molecular basis of sensitive skin and the suitable neurocosmetic ingredients to improve this problem are discussed. With the aim of presenting the major application of Botox-like ingredients as the first neurocosmetics on the market, skin aging is also introduced, and its theory is presented. To confirm the efficacy of the cosmetic products on the market, the concept of cosmetic claims is discussed.

Complications and Adverse Effects of Periocular Aesthetic Treatments

The popularity and variety of temporary and permanent periocular aesthetic treatments has increased over the past decade. Patients frequently present to eye clinics with ocular complications and side effects following these treatments, their severity ranging from ocular irritation from dry eyes to visual loss from vascular occlusion. A careful, thorough history is essential, as many patients may not associate aesthetic procedures with ocular complications, and some may be embarrassed to disclose this information. All ophthalmologists should understand the potential ocular sequelae of these treatments and be able to initiate treatment in sight-threatening cases. Wesummarises the current literature on ophthalmic complications of the most common periocular aesthetic treatments.

Use of AbobotulinumtoxinA for Cosmetic Treatments in the Neck, and Middle and Lower Areas of the Face: A Systematic Review

AbobotulinumtoxinA (aboBoNT-A) has been used for various cosmetic purposes, including minimization of moderate to severe lines, or other cosmetic indications, in the face and neck. We carried out a systematic review to identify all relevant evidence on the treatment approaches and outcomes of aboBoNT-A as a cosmetic treatment of the middle and lower areas of the face, and the neck. Embase, MEDLINE, Cochrane Library, congress proceedings and review bibliographies were searched for relevant studies. Identified articles were screened against pre-specified eligibility criteria. Of 560 unique articles identified, 10 were included for data extraction (three observational studies, 1 randomized controlled trial [with two articles] and five non-randomized trials). The articles provided data on gummy/asymmetric smile (2), marionette lines (5), masseter muscle volume (2), nasal wrinkles (2), perioral wrinkles (3) and the platysma muscle (4). All articles reporting on efficacy of aboBoNT-A demonstrated positive results, including reduction of wrinkles (5), reduction of masseter muscle (2) and degree of gummy smile (1) compared with before treatment. No serious adverse events were reported and patient satisfaction was high. In conclusion, positive findings support further research of aboBoNT-A for the middle and lower areas of the face, and in the neck, which are largely unapproved indications.

The minimum effective dose of abobotulinum toxin A injection for allergic rhinitis: A dose-escalation randomized controlled trial

OBJECTIVE

To find the lowest effective injection dose of abobotulinum toxin A (Dysport) for allergic rhinitis.

STUDY DESIGN

Dose-escalation randomized controlled trial.

METHODS

We included all patients aged 18 years or older who had persistent allergic rhinitis and positive allergy skin prick test. The patients were randomly allocated to receive 40, 30, or 20 U of abobotulinum toxin A by injection at the inferior turbinate. We followed up on patients for 12 weeks to evaluate nasal symptoms, ocular symptoms, minimum nasal cross-sectional area as measured using acoustic rhinometry, and complications.

RESULTS

Seventeen patients were included in this study, with 7 receiving 20 U of abobotulinum toxin A and 5 each receiving 30 U and 40 U. Abobotulinum toxin A significantly improved nasal congestion, rhinorrhea, sneezing, and loss of smell at 40 U (P < .05) and nasal congestion, sneezing, and loss of smell at 30 U (P < .05). However, at a dose of 20 U, only nasal congestion and loss of smell improved (P < .05). Nasal patency had also significantly improved two weeks after treatment at doses of 40 and 30 U (P < .05). Complications included epistaxis (11.8%) and nasal dryness (23.5%).

CONCLUSION

Abobotulinum toxin A at a dose of at least 30 U effectively reduced most nasal symptoms.

LEVEL OF EVIDENCE

2.

TRIAL REGISTRATION

Clinicaltrials.in.th/ TCTR20200526014.

Comparative Pharmacodynamics Study of 3 Different Botulinum Toxin Type A Preparations in Mice

A new complexing protein-free botulinum toxin Type A (CBoNT) with the same mechanism of action as the botulinum toxin complex onabotulinumtoxinA (OBoNT) and complexing protein-free incobotulinumtoxinA (IBoNT) was recently developed.

Perspective of an International Online Patient and Caregiver Community on the Burden of Spasticity and Impact of Botulinum Neurotoxin Therapy: Survey Study

Background

Patient- and caregiver-reported data are lacking on the burden of spasticity, and the impact of botulinum neurotoxin type A (BoNT-A) treatment for this condition, on patients' daily lives. As recommended in recent guidance from the US Food and Drug Administration, online patient communities can represent a platform from which to gather specific information outside of a clinical trial setting on the burden of conditions experienced by patients and caregivers and their views on treatment options in order to inform evidence-based medicine and drug development.

Objective

The objective of our study is to characterize spasticity symptoms and their associated burdens on Western European and US patients and caregivers in the realms of work, daily activities, quality of life (QoL), as well as the positive and negative impacts of treatment with BoNT-A (cost, time, QoL) using Carenity, an international online community for people with chronic health conditions.

Methods

We performed a noninterventional, multinational survey. Eligible participants were 18 years old or older and had, or had cared for, someone with spasticity who had been treated with BoNT-A for at least 1 year. Patients and caregivers were asked to complete an internet-based survey via Carenity; caregivers reported their own answers and answered on behalf of their patients. Questions included the burden of spasticity on the ability to work, functioning, daily-living activities, and QoL, the impact of BoNT A therapy on patients' lives, and the potential benefits of fewer injections.

Results

There were 615 respondents (427 patients and 188 caregivers). The mean age of patients and caregivers was 41.7 years and 38.6 years, respectively, and the most commonly reported cause of spasticity was multiple sclerosis. Caregivers were most often the parents (76/188, 40%) or another family member (51/188, 27%) of their patients. Spasticity had a clear impact on patients' and caregivers' lives, including the ability to work and injection costs. For patients, spasticity caused difficulties with activities of daily living and reduced QoL indices. The median number of BoNT-A injections was 4 times per year, and 92% (393/427) of patients reported that treatment improved their overall satisfaction with life. Regarding the BoNT-A injection burden, the greatest patient-reported challenges were the cost and availability of timely appointments. Overall, 86% (368/427) of patients believed that a reduced injection frequency would be beneficial. Caregivers answering for their patients gave largely similar responses to those reported by patients.

Conclusions

Spasticity has a negative impact on both patients' and caregivers' lives. All respondents reported that BoNT A treatment improved their lives, despite the associated challenges. Patients believed that reducing the frequency of BoNT-A injections could alleviate practical issues associated with treatment, implying that a longer-acting BoNT-A injection would be well received.

Bioactivity of abobotulinum toxin is preserved till 2 weeks upon storage at room temperature: Half body comparative study on rabbit model

BACKGROUND

Breakages of the cold chain of botulinum neurotoxin A (BONT-A) preparations is not a rare event and occurs due to several unexpected and unintentional reasons during daily practice and intervention schedules could not be proposed due to the lack of data.

OBJECTIVE

To investigate the heat stability of abobotulinum toxin A (AboBONT-A) in terms of efficacy and duration of action upon storage at room temperature (25°C) for 2, 4, and 8 weeks.

METHODS AND MATERIALS

Twenty rabbits were divided into four groups and received an injection of ideally stored AboBONT-A (Group 1) and stored AboBONT-A for 2 (Group 2), 4 (Group 3), and 8 weeks (Group 4) at room temperature into the anterior auricular muscle. All rabbits were followed up and photographed by weekly for 16 weeks. Grade of paralysis was evaluated by using a modified visual scoring system.

RESULTS

No significant alteration was found in initial potency of stored AboBONT-A at room temperature for up to 4 weeks. Storage at room temperature for 2 weeks did not affect the duration of action (group 2; P = .69), and faster recovery was observed in group 3 and group 4.

CONCLUSION

The bioactivity of AboBONT-A is not altered till 2 weeks upon storage at room temperature.

Prehabilitation of complex ventral hernia patients with Botulinum: a systematic review of the quantifiable effects of Botulinum

PURPOSE

Complex ventral hernia repair (CVHR) encompasses patient optimization, primary fascial closure (PFC), mesh reinforcement and component separation technique (CST), if needed. High rates of complications after CST are still reported. Prehabilitation by managing pre-operative modifiable risk factors, like abdominal wall compliance, possibly reduces these rates. Compliance can be modified by intramuscular injection of Botulinum in the lateral abdominal wall muscles (LAWM). Paralysis leads to elongation of these muscles, which may facilitate PFC and/or prevent CST. Evidence to use Botulinum in hernia patients is scarce and fragmented. An update of evidence for the effect of Botulinum is presented.

METHODS

A multi-database search was conducted for Botulinum studies in ventral hernia patients. A systematic review was performed to describe its primary effect on compliance (LAWM elongation) and secondary effects like PFC ± CST rate, complications and recurrence.

RESULTS

14 studies were included (377 patients) with a HDW of median 12 (10-15) cm. A typical intervention consisted of 200-300 U Botulinum in 3 points per hemi-abdomen under US guidance, > 2 weeks pre-operatively and evaluated by CT just before the operation. The primary effect was a median LAWM elongation of 4.0 cm per side without complications of the injection (four studies, 107 patients). The median PFC rate was 100%, CST rate 38%, wound-related complications 19%, medical complications 18% and recurrence 0% (14 studies).

CONCLUSION

Botulinum safely elongates the abdominal wall muscles, but the level of evidence available remains low. Any patient in whom PFC is expected to be difficult, could be a candidate for prehabilitation with Botulinum.

A Novel OnabotulinumtoxinA Treatment Technique to Obtain Predictable Outcomes in Eyebrow Position and Shape

Background

OnabotulinumtoxinA has been approved for multiple clinical and dermatological indications. The toxin, produced by the bacterium Clostridium botulinum, is undoubtedly the most widely used cosmetic treatment for both the reduction and prophylaxis of wrinkles in the upper face and the reshaping of the eyebrows. However, the aesthetic outcomes obtained with respect to eyebrow position and shape are not always predictable and furthermore, untoward effects such as eyelid and brow ptosis are sometimes seen.

Objective

This article suggests a novel injection technique of the upper face with OnabotulinumtoxinA to obtain predictable and reproducible results with respect to eyebrow position and shape, whilst greatly minimizing the risk of adverse effects such as brow and lid ptosis.

Discussion

OnabotulinumtoxinA inhibits the release of acetylcholine and results in the temporary paralysis of skeletal muscle. The aesthetic outcome of wrinkle reduction typically lasts for a period of 14–16 weeks. Although relatively safe in that the toxin does not have any irreversible side effects, even a temporary untoward reaction may be seriously distressing to the cosmetic patient.

Conclusion

The proposed injection technique, when diligently followed, ensures that the final eyebrow position is pleasing and symmetrical with a negligible risk of any untoward effects.

The mechanisms of action and use of botulinum neurotoxin type A in aesthetics: Key Clinical Postulates II

BACKGROUND

The literature on botulinum neurotoxin type A (BoNT-A) is extensive, often contradictory, and confounded by a competitive market of products and research attempting to distinguish brand individuality.

METHODS

A comprehensive review of literature on the principles of BoNT-A in aesthetics as well as clinical examples.

RESULTS

In 2017, the Eight Key Clinical Postulates were formulated as a guide for the aesthetic practitioner in understanding BoNT-A pharmacodynamics and to compare different toxins. These are now updated to include (a) All type A toxins act identically; (b) The mathematical relationship between toxin and receptor is the basis of efficacy, and clinical efficacy is influenced by molecular potency and patient attributes including muscle mass, gender, age, and ethnicity; (c) Efficacy, onset, and duration are functions of "molecular potency" defined as the number of active 150 kDa molecules available for binding; (d) "Molecular potency" is difficult to objectively quantify for commercially available toxins; (e) Up to a point, increased molecular potency decreases time to onset and increases duration of effect, and the "Molecular Potency Quotient" is a construct for comparing molecular potency commercial cost; (f) The area of effect of a toxin injection is dependent upon molecular potency, diffusion (passive), and spread (active); (g) Differing reconstitution volumes; and (h) Increased number of injection sites can affect spread, onset, and duration of effect.

CONCLUSIONS

The principles of BoNT-A use in aesthetics are complex yet understandable as outlined in the framework of the updated Eight Key Clinical Postulates and serves as a useful tool for providing the most effective treatment and interpreting research on present and future toxin formulations.

A Nurse-Led Clinic Model for the Treatment of Cervical Dystonia Using Botulinum Toxin

Dystonia is a neurological movement disorder characterised by sustained or intermittent muscle contractions, producing abnormal and often repetitive movements, abnormal posture or both. It is often accompanied by chronic pain, depression and anxiety. The treatment of dystonia is primarily symptomatic, designed to improve posture and function and to relieve associated pain. This can include oral medications, botulinum toxin (BoNT) injection, and deep brain stimulation (DBS). This article will focus on BoNT treatment, which is just one facet in the treatment of cervical dystonia. The involvement of clinical nurse specialists and the use of a nurse-led clinic can increase efficiency and effectiveness (namely, increased clinic efficiency and capacity, reduced appointment waiting times, and improved continuity of care for the patients), as well as patient access, education, psychosocial support, monitoring and, ultimately, empowerment. This article will discuss the key elements, considerations and benefits of setting up a nurse-led clinic for patients with dystonia.

Botulinum toxin injections for shoulder and upper limb pain: a narrative review

Botulinum toxin (BoNT) has been widely employed to treat poststroke spasticity, cervical dystonia and muscle hyperactivity. Recently, BoNT injections are increasingly used in treating musculoskeletal pain. The mechanism of BoNT in pain relief comprises relaxation of overused muscles and inhibition of inflammatory nociceptive cytokines/neurotransmitters. As BoNT injections seem promising in treating painful musculoskeletal disorders, we aimed to investigate its effectiveness in shoulder and upper limb pain. Although the present article is a narrative review, we employed a systematic approach to search for relevant articles in PubMed. A total of 19 clinical studies were included. Here, we observed that intramuscular BoNT injections were helpful in stroke patients with hemiplegic shoulder pain. In shoulder joint pain, intra-articular and intrabursal BoNT injections achieved a longer period of pain relief than corticosteroid injections. Similarly, a more durable effect of intramuscular BoNT than saline injections was seen in shoulder myofascial pain. Its use in complex regional pain syndrome and persistent upper limb pain in breast cancer survivors was insufficient, necessitating more studies. Since not all of the included studies could provide Class I of evidence based on the efficacy criteria used by American Academy of Neurology, controlled clinical trials in a larger number of patients are necessary to verify validity of these findings in the future.