Conversion Ratio between Botox®, Dysport®, and Xeomin® in Clinical Practice

A Functional Approach to Posttraumatic Salivary Fistula Treatment: The Use of Botulinum Toxin

This manuscript highlights key aspects regarding the practical use of botulinum toxin for the conservative nonsurgical treatment of a rarely encountered, but significant posttraumatic complication-the parotid salivary fistula. It adds information to the scarce existing literature on the subject. The authors outline the main differences between postoperative and trauma-related parotid injury regarding salivary fistula treatment. A total of 6 patients with trauma-related salivary fistulas have been treated by Abobotulinum toxin A injections over the course of 5 years. The technique is detailed, describing the doses used in the presence of parenchyma and duct injuries, the location and number of injection points in relation to the wound pattern. The results were favorable, leading to the healing of the salivary fistulas in all patients, with 1 injection session, without additional conservative treatment. In our experience, the use of botulinum toxin is of great benefit for treating salivary fistulas in a traumatic context.

Botulinum Toxins Type A (Bont-A) in the Management of Lower Limb Spasticity in Children: A Systematic Literature Review and Bayesian Network Meta-analysis

BACKGROUND

Botulinum neurotoxins type A (BoNT-As) are used in pediatric lower limb spasticity, which affects more than 2.5 million children worldwide. Botulinum neurotoxins type-A improve active function and delay musculoskeletal complications. The objective of this analysis was to evaluate the efficacy and safety of abobotulinumtoxinA versus other botulinum neurotoxins type A in pediatric spasticity, in the absence of head-to-head evidence.

METHODS

A systematic literature review was conducted to identify relevant randomized controlled trials. The evidence base was synthesized with Bayesian network meta-analyses. Outcomes analyzed included Modified Ashworth Scale, Tardieu Scale (TS) spasticity grade, and Goal Attainment Scale (standard mean difference only) at 12 weeks postinjection, and adverse events occurring during study periods.

RESULTS

Thirty-eight studies were identified, 10 of which met inclusion criteria for quantitative synthesis. On Modified Ashworth Scale, abobotulinumtoxinA 15 U/kg/leg was significantly more efficacious than onabotulinumtoxinA 4 U/kg/leg (-0.99 [-1.34, -0.64]) and onabotulinumtoxinA 4 U/kg/leg+casting (-0.81 [-1.16, -0.46]) and numerically better than onabotulinumtoxinA 8 U/kg (-0.40 [-0.67, -0.14]). AbobotulinumtoxinA 10 U/kg/leg was significantly more efficacious than onabotulinumtoxinA 4 U/kg/leg (±casting). On Goal Attainment Scale, abobotulinumtoxinA 15 U/kg/leg and 10 U/kg/leg were significantly more efficacious than onabotulinumtoxinA 12 U/kg/leg. On Tardieu Scale spasticity grade, abobotulinumtoxinA was comparable to other treatments. AbobotulinumtoxinA demonstrated adverse event rates comparable to all doses of onabotulinumtoxinA.

CONCLUSIONS

In pediatric lower limb spasticity, abobotulinumtoxinA offered significant or numerical efficacy advantages on tone (Modified Ashworth Scale) and functional outcomes (Goal Attainment Scale), and comparable efficacy on Tardieu Scale spasticity grade. AbobotulinumtoxinA was comparable to onabotulinumtoxinA on tolerability. Results should be interpreted in the context of heterogeneity and sparsity of the evidence base.

The Use of Botulinum Toxin in Strabismus Treatment

There is a long and extensive experience with the use of Botulinum Toxin type A (BoNT-A) injection in the treatment of different types of strabismus and oculomotor palsies. The frequency of its use varies depending on the country and institution. It is a short procedure, may reduce general anesthesia exposure, causes minimal scarring compared to surgery, and can be proposed as an early treatment in unstable strabismus. Over many years, the experience of using BoNT-A indications has been refined and new applications have been reported. The use of BoNT-A in the postoperative period, after strabismus surgery or during surgery, can also be beneficial.

Botulinum Toxin Treatment for Mild to Moderate Platysma Bands: A Systematic Review of Efficacy, Safety, and Injection Technique

Background

Platysma bands are characteristic of an aging neck. Resection and plication of the platysma muscle is the basis of treatment. However, unfavorable surgical outcomes and improved understanding of platysma band etiology have shifted treatment towards nonsurgical rejuvenation.

Objectives

The aim of this paper was to assess the efficacy, injection techniques, and complications associated with botulinum toxin injection for the treatment of platysma bands.

Methods

A systematic literature search was performed to identify articles reporting botulinum toxin injections for platysma bands in neck rejuvenation. The search included published articles in three electronic databases-Ovid MEDLINE, EMBASE, and the Cochrane Library-between January 1985 and December 2017.

Results

Three studies met the inclusion criteria, with a total of 78 patients undergoing botulinum toxin injection for platysma bands. Incobotulinumtoxin A was used in 62.3% (n = 45/78) of patients, with 38.4% (n = 30/78) receiving abobotulinumtoxin A. Efficacy was assessed using the Merz platysma score scale. A mean score improvement of 2.0 points, with a response rate of 93.7%, was observed after 14 ± 2 days. At 3 months, the mean score improvement was 1.2 points with a response rate of 86%. Patient-reported metrics demonstrated an improvement in 91% (n = 71/78) of subjects. The three studies used a standard injection technique, with a maximum 20 IU of incobotulinumtoxin A and 5 U abobotulinumtoxin A administered per band. Complications were reported in 15.4% (n = 12/78) of patients, with none requiring further intervention.

Conclusions

Botulinum toxin is a highly effective treatment for isolated platysma bands. A safe injection technique is described and recommended for clinical practice.

Level of Evidence 4

Clinical Pharmacology of Botulinum Toxin Drugs

Botulinum toxin (BT) has changed from a deadly poison to a novel therapeutic principle for a large number of disorders in many medical areas.BT drugs are special in many ways: they are biologicals, their active ingredient BT is not patentable, their spectrum of clinical applications is extremely broad, their dose range is enormous, their mode of action is local and their life cycles are special.This review covers BT's therapeutic mode of action, time course of action, target tissues, pharmacological profile, adverse effects, interactions, potency labelling and antigenicity as well as BT's therapeutic preparations.

Contemporary Review and Case Report of Botulinum Resistance in Facial Synkinesis

BACKGROUND

Botulinum resistance poses significant treatment challenges for both patients and healthcare practitioners. We first present a case highlighting botulinum resistance in a patient who failed to respond to alternative formulations but who responded remarkably to incobotulinum toxinA, an identical toxin free of complexing proteins. Secondly, we provide a treatment algorithm and a review of the literature detailing clinical and immunochemical botulinum resistance.

RESULTS

Patients with botulinum resistance show a predisposition to failure on subsequent injections and possess a propensity toward neutralizing and nonneutralizing antibody development. The mechanisms of resistance are not entirely understood but thought to be secondary to an immunologic response. Risk factors for resistance include higher botulinum doses, more frequent injections, and high total lifetime dosage. Patients may still respond to other botulinum formulations or subtypes; however, this effect may be temporary.

CONCLUSION

This case report describes a patient who responded to incobotulinum toxinA after failing treatment with the identical toxin compounded with buffer proteins, ultimately supporting the possibility of immune-mediated resistance to the surrounding proteins and not the toxin itself. Often, impending treatment resistance is preceded by a poor or limited clinical response. Antibody testing is not indicated because it is neither sensitive nor specific and does not change clinical practice. Initially, higher doses of botulinum may overcome resistance without increasing treatment frequency, and side effects are far less common in those with clinical resistance. If higher dosages fail to produce a response, alternative botulinum formulations or subtypes can be considered. Laryngoscope, 129:2269-2273, 2019.

Endoscopic Botulinum Toxin for Gastroparesis: Results of a Retrospective Series

Beneficial effects of pyloric botulinum toxin injection have been described in a subgroup of gastroparesis patients. Our aim is to evaluate whether clinical, manometric and/or scintigraphic parameters are able to predict treatment outcome. Forty patients (67% female, age 49 (36–56) years) with decompensated gastroparesis treated with botulinum toxin were included in this retrospective analysis. Objective parameters were high-resolution antroduodenal manometry, gastric emptying rate (scintigraphy), and weight change. Subjective treatment outcome was assessed with a Global Physician Assessment Scale. Binary logistic regression analysis was performed to identify predictors for treatment outcome. Fourteen patients (35%) were symptom-responders, and 65% of patients were short-term weight-responders. For both subjective and objective treatment outcome, no differences were found in manometric and scintigraphic variables between responders and non-responders. Neither clinical nor manometric or scintigraphic variables could predict subjective and objective treatment outcome. In conclusion, symptom improvement is achieved in a subgroup of gastroparesis patients treated with endoscopic pyloric botulinum toxin. Although the majority of patients were able to maintain their baseline weight at short-term follow-up, a substantial group of patients needed nutritional interventions on long-term follow-up. However, none of the demographic, clinical, scintigraphic, or antroduodenal manometry variables were able to predict either subjective or objective treatment outcome.

A prospective randomized clinical trial comparing two doses of AbobotulinumtoxinA for idiopathic overactive bladder

AIMS

To compare 300 U versus 500 U of abobotulinumtoxinA (ABO) intravesical injections for the treatment of idiopathic overactive bladder (OAB) refractory to first and second-line treatments.

METHODS

A prospective, randomized, single blind study was performed in female patients with symptoms of OAB, who had failed conservative treatment. Patients were treated with 300 or 500 U of ABO injected into 30 sites, avoiding the trigone. All treatments were evaluated by voiding diary, ICIQ-OAB questionnaire, urodynamic test, visual analogue scale (VAS) for treatment satisfaction and patient global impression of improvement (PGI-I). The primary outcome was change in maximum cistometric capacity (MCC). Secondary outcome included changes in urgency, complete continence, subjective success (VAS and PGI-I), and adverse events (urinary retention, UTI, and CIC).

RESULTS

Twenty-one patients were included. MCC has increased from 185.0 to 270.9 mL (300 U) and from 240.8 to 311.7 mL (500 U), comparing the baseline with 12 weeks, without statistical difference between the groups (P = 0.270). At 12 weeks, 91% of patients were dry in both groups. At 24 weeks, episodes of incontinence had returned in 50% (300 U) and 0% (500 U) (P = 0.013). Patients were better or much better (PGI-I) in70% (300 U) and 88.9% (500 U) at 12 w; and 50% (300 U) and 100% (500 U), at 24 w (P = 0.027). The peak of PVR was at 4 w, being 71.7 mL (300 U) and 96.5 mL (500 U). General UTI incidence was 35.7%. One patient (500 U) required CIC for 2 weeks.

CONCLUSIONS

Intravesical ABO injection at 500 U improves symptoms and quality of life for longer period of time than 300 U for idiopathic OAB.

Treatment of non-odontogenic orofacial pain using botulinum toxin-A: a retrospective case series study

BACKGROUND

The purpose of this study was to evaluate the clinical outcomes of treatment of non-odontogenic atypical orofacial pain using botulinum toxin-A.

METHODS

This study involved seven patients (seven females, mean age 65.1 years) who had non-odontogenic orofacial pain (neuropathic pain and atypical orofacial pain) and visited the Seoul National University Bundang Hospital between 2015 and 2017. All medication therapies were preceded by botulinum toxin-A injections, followed by injections in the insignificant effects of medication therapies. Five of the seven patients received intraoral injections in the gingival vestibule or mucosa, while the remaining two received extraoral injections in the masseter and temporal muscle areas.

RESULTS

In five of the seven patients, pain after botulinum toxin-A injection was significantly reduced. Most of the patients who underwent surgery for dental implantation or facial nerve reconstruction recovered after injections. However, the pain did not disappear in two patients who reported experiencing persistent pain without any cause.

CONCLUSIONS

The use of botulinum toxin-A for the treatment of non-odontogenic neuropathic orofacial pain is clinically useful. It is more effective to administer botulinum toxin-A in combination with other medications and physical therapy to improve pain.

High prevalence of neutralizing antibodies after long-term botulinum neurotoxin therapy

Objective

To investigate the prevalence of neutralizing antibodies (NAbs) against botulinum neurotoxin type A (BoNT/A) during long-term BoNT/A treatment in different neurologic indications.

Methods

In this monocentric, observational cross-sectional study, 596 outpatients treated with BoNT/A for different indications were tested for BoNT/A binding antibodies by ELISA. Positive samples were investigated for NAbs with the mouse hemidiaphragm test. The prevalence of NAbs was analyzed for different indications: facial hemispasm, blepharospasm, cervical dystonia, other dystonia, and spasticity. Besides the rate of NAb-positive patients overall and per patient subgroup, a Kaplan-Meier analysis of the probability of remaining NAb negative with duration of treatment is provided, and a stepwise binary logistic regression analysis is performed to identify factors significantly contributing to the induction of NAbs.

Results

Overall, 83 of 596 patients (13.9%) had measurable NAbs. The probability of developing NAbs increased with the single and cumulative dose of treatment and was influenced by the BoNT/A formulation, while all other factors analyzed, including disease entity and treatment duration, had no additional influence.

Conclusions

We present the largest study to date of the prevalence of BoNT/A NAbs in a large unbiased cohort of patients including the relevant neurologic indications. Repeated injections of BoNT/A inevitably bear the risk of developing NAbs. However, in addition to avoiding booster injections and providing short intervals between injections, reducing the individual injected doses may diminish the risk of NAb induction independently of the indication for which BoNT/A is used.

Efficacy and Safety of Botulinum Toxin Type A in Spasticity Caused by Spinal Cord Injury: A Randomized, Controlled Trial

Background

Baclofen is approved by the US FDA to treat spasticity, but its sustained use may cause drug addiction. The objective of this study was to compare the efficacy and safety of botulinum toxin type A versus baclofen in spasticity.

Material/Methods

A total of 336 patients who had spasticity caused by spinal cord injury were enrolled in a randomized (in 1: 1: 1: ratio) for placebo, controlled trial. Patients had received baclofen (BA group, n=112), local intramuscular injection of 500 U Botulinum toxin type A (BTI group, n=112), or physical therapies alone (placebo group, n=112). Modified Ashworth scale (mAS) score, disability assessment scale (DAS) score, modified medical research council (mMRC) score, the Barthel Index (BI) score, and treatment-emergent adverse effects were evaluated during the follow-up period. Wilcoxon test or one-way ANOVA/Tukey post hoc tests were performed at 95% of confidence level.

Results

Baclofen (1.504±0.045 vs. 1.53±0.06, p=0.003, q=4.068) and botulinum toxin type A (1.49±0.09 vs. 1.528±0.15, p=0.0224, q=3.5541) had improved mAS scores after 2 weeks. Baclofen had a more strongly improved DAS score than botulinum toxin type A at 4 (p=0.0496, q=3.48) and 6 (p<0.0001, q=6.48) weeks. Baclofen and botulinum toxin type A had consistently improved BI scores. Baclofen caused asthenia and sleepiness, while botulinum toxin type A caused bronchitis and elevated blood pressure.

Conclusions

Botulinum toxin type A may be an effective therapeutic option for spasticity caused by spinal cord injury.

Management and Follow-up Results of Salivary Fistulas Treated With Botulinum Toxin

OBJECTIVES/HYPOTHESIS

Salivary fistulas are a common minor complication of parotid surgery. botulinum toxin has repeatedly been reported to be an adequate treatment of this entity. To date, there is little scientific evidence for clinical decision making after appearance of a salivary fistula.

STUDY DESIGN

Retrospective chart analysis of 16 patients who had been treated with botulinum toxin for salivary fistula.

METHODS

All patients who had been treated for salivary fistula at a tertiary referral hospital from 2010 to 2016 were included. Patient files were used to obtain characteristics of patients, treatment, and follow-up.

RESULTS

Sixteen patients with salivary fistula received 27 injections of botulinum toxin. Nine patients required one injection for the fistula to heal, five patients needed two injections, and one patient needed three and four injections, respectively. No patient underwent additional surgery or radiotherapy. We observed no adverse effects in any patient treated with botulinum toxin.

CONCLUSIONS

In most cases of salivary fistula, injections of botulinum toxin are a valid treatment. If the initial injection is not successful, injections may be repeated once. Otherwise, revision surgery should be considered. In general, treatment with botulinum toxin should be commenced in an earlier stage and with higher dosages.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:403-408, 2019.

In vitro potency determination of botulinum neurotoxin serotype A based on its receptor-binding and proteolytic characteristics

Botulinum neurotoxins (BoNTs) inhibit the release of the neurotransmitter acetylcholine from motor neurons, resulting in highly effective muscle relaxation. In clinical and aesthetic medicine, serotype BoNT/A, which is most potent for humans, is widely used to treat a continuously increasing spectrum of disorders associated with muscle overactivity. Because of the high toxicity associated with BoNTs, it is mandatory to precisely determine the potency of every batch produced for pharmaceutical purposes. Here we report a new quantitative functional in vitro assay for BoNT/A. In this binding and cleavage (BINACLE) assay, the toxin is first bound to specific receptor molecules. Then a chemical reduction is performed, thereby releasing the light chain of BoNT/A and activating its proteolytic domain. The activated light chain is finally exposed to its substrate protein SNAP-25, and the fragment resulting from the proteolytic cleavage of this protein is quantified in an antibody-mediated reaction. The BoNT/A BINACLE assay offers high specificity and sensitivity with a detection limit below 0.5 mouse lethal dose (LD₅₀)/ml. In conclusion, this new in vitro assay for determining BoNT/A toxicity represents an alternative to the LD₅₀ test in mice, which is the "gold standard" method for the potency testing of BoNT/A products.

Unilateral Botulinum Neurotoxin-A Injection into the Striatum of C57BL/6 Mice Leads to a Different Motor Behavior Compared with Rats

Different morphological changes in the caudate-putamen (CPu) of naïve rats and mice were observed after intrastriatal botulinum neurotoxin-A (BoNT-A) injection. For this purpose we here studied various motor behaviors in mice (n = 46) longitudinally up to 9 months after intrastriatal BoNT-A administration as previously reported for rats, and compared both outcomes. Apomorphine- and amphetamine-induced rotational behavior, spontaneous motor behavior, as well as lateralized neglect were studied in mice after the injection of single doses of BoNT-A into the right CPu, comparing them with sham-injected animals. Unilateral intrastriatal injection of BoNT-A in mice induced significantly increased contralateral apomorphine-induced rotations for 1 to 3 months, as well as significantly increased contralateral amphetamine-induced rotations 1 to 9 months after injection. In rats (n = 28), unilateral BoNT-A injection also induced significantly increased contralateral apomorphine-induced rotations 3 months after injection, but did not provoke amphetamine-induced rotations at all. Lateralized sensorimotor integration, forelimb preference, and forelimb stepping were significantly impaired on the left side. The differences in motor behaviors between rats and mice may be caused by different BoNT-A effects on cholinergic and catecholaminergic fibers in rat and mouse striata, interspecies differences in striatal receptor densities, and different connectomes of the basal ganglia.

Comparing incobotulinumtoxinA (Xeomin®) and onabotulinumtoxinA (Botox®): identical potency labelling in the hemidiaphragm assay

Botulinum toxin (BT) is provided by several manufacturers producing a number of different drugs. Their potency is given in internationally standardised mouse units (MU). Clinical practise, however, reveals that the potency labelling of different BT drugs may not be identical. We wanted to use the mouse diaphragm assay (MDA) to compare the two BT drugs onabotulinumtoxinA (ONA) and incobotulinumtoxinA (INCO). For this, we measured the paresis time (PT) of different ONA or INCO doses. All BT came from several different and unexpired drug batches. PT for 20MU were 169.7 ± 28.9 min (ONA) and 132.3 ± 1.5 min (INCO) (p = 0.089), for 60MU 105.3 ± 10.1 min and 84.7 ± 4.2 min (p = 0.031), for 100MU 69.7 ± 1.5 min and 66.0 ± 7.0 min (p = 0.462) and for 140MU 74.7 ± 0.6 min and 62.3 ± 2.1 min (p = 0.100), respectively. The overall PT were 104.8 ± 12.5 and 86.3 ± 8.5 min (p = 0.178). Results presented here do not reveal differences in potency labelling between ONA and INCO, even when the full range of therapeutic doses are examined, although there was a trend towards stronger INCO effects. Data confirm previous reports on identical potency labelling of ONA and INCO. The MDA seems to be an appropriate instrument to test the potency labelling of other BT drugs as well, including new BT drugs currently under development.

Botulinum neurotoxin formulations: overcoming the confusion

Botulinum toxin A is produced by anaerobic spore-forming bacteria and is used for various therapeutic and cosmetic purposes. Botulinum toxin A injections are the most popular nonsurgical procedure worldwide. Despite an increased demand for botulinum toxin A injections, the clinical pharmacology and differences in formulation of commonly available products are poorly understood. The various products available in the market are unique and vary in terms of units, chemical properties, biological activities, and weight, and are therefore not interchangeable. For safe clinical practice and to achieve optimal results, the practitioners need to understand the clinical issues of potency, conversion ratio, and safety issues (toxin spread and immunogenicity). In this paper, the basic clinical pharmacology of botulinum toxin A and differences between onabotulinum toxin A, abobotulinum toxin A, and incobotulinum toxin A are discussed.

Short-Term Effect of Low-Dose, Electromyography-Guided Botulinum Toxin A Injection in the Treatment of Chronic Lateral Epicondylar Tendinopathy: A Randomized, Double-Blinded Study

BACKGROUND

Botulinum toxin A (BoNT-A) is a novel treatment for chronic lateral epicondylar tendinopathy. Preliminary studies have demonstrated promising results; however, confirmation of the effectiveness of BoNT-A treatment and further assessment of its side effects are required. This study investigated the analgesic effects of BoNT-A in the treatment of chronic lateral epicondylar tendinopathy.

METHODS

This was a phase-III, single-center, randomized, double-blinded, placebo-controlled study including 60 patients with chronic lateral epicondylar tendinopathy that had been resistant to treatment for >6 months. Patients received either a 40-IU injection of BoNT-A or saline solution placebo into the extensor carpi radialis brevis (ECRB) muscle, aided by electromyographic (EMG) stimulation. Follow-up was 3 months. The primary assessment criterion was the percentage of patients whose pain was reduced by >50% at 90 days after injection. Secondary outcomes, including pain intensity, pain frequency, interference with quality of life, sick leave taken, maximum grip strength, and side effects, were assessed at days 30 and 90, and the number of participants per group requesting additional therapies at day 90 was recorded.

RESULTS

Twenty-nine patients in the BoNT-A group and 28 patients in the placebo group were included in the day-90 analysis. Fifteen (51.7%) of the patients who were administered BoNT-A and 7 (25%) of the patients who received placebo reported a >50% reduction in initial pain intensity at day 90 (p = 0.005). Pain intensity and the effect on quality of life, measured using visual analog scales, were both significantly lower in the group treated with BoNT-A compared with placebo at day 90 (p < 0.05). The rate of clinically detected transitory paresis of the third finger on extension was 17.2% in the BoNT-A group, with no associated functional impairment.

CONCLUSIONS

BoNT-A at 40 IU injected into the ECRB is an effective treatment for chronic lateral epicondylar tendinopathy that has been otherwise resistant to medical treatment. The rate of paresis of the third finger was low, with no associated functional impairment.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Globular chitosan prolongs the effective duration time and decreases the acute toxicity of botulinum neurotoxin after intramuscular injection in rats

Botulinum neurotoxin (BoNT) is used for an increasing number of neurological and non-neurological indications and disorders. Since the duration of action of this neurotoxin is limited, the goal of the work was to improve the pharmacological time course of BoNT. We explored the effect of several polysaccharides on the duration of action of BoNT/A1 in rat electromyography. The formulation of BoNT/A1 containing globular chitosan increased the threshold stimulation intensity almost 2 times in 30 days after injection if compared with the baseline threshold. However, conventional linear chitosan, heparin and hyaluronic acid did not have such an effect. In addition, we compared the effectiveness of different doses of BoNT/A1 (25, 50, 75, and 100 U) with globular chitosan and compared the acute toxicity of this formulation with that of BoNT/A1 in physiological saline after intramuscular injection. The results demonstrated that the dose 25 U of BoNT/A1 with globular chitosan was both effective and safe for animals after intramuscular injection. The assessed median lethal dose (LD₅₀) for intramuscular injection in rats was 1.4 times higher for a combination of BoNT/A1 with globular chitosan than that for a solution of BoNT/A1 in physiological saline. Thus, the results of our study have provided evidence that intramuscular injection of the formulation of BoNT/A1 (25 U) containing globular chitosan in rats is safe and significantly prolongs the effective duration time of BoNT/A1.

[Conversion ratio between different botulinum neuroprotein product in neurological practice]

Despite nearly 30 years of experience in the application of botulinum toxin type A (BTA) in clinical practice, many fundamental questions of therapy remain valid. There are 5 botulinum toxin type A used for neurological indications in the Russian Federation in 2017. They contain different number of active neuroprotein (150 kDa) in a therapeutic dose of the drug that may have a potential impact on the efficacy and duration of action. The current SmPC of each BTA stated that the unit of activity is unique and can not be compared with any other BTA. In scientific publications one can find many details concerning the equivalence doses of onabotulinumtoxin A (botox) and abobotulinumtoxin A (dysport) and the ratio of units varies from 1:1 to 1:11. However, according to clinical guidelines, systematic reviews and high quality research evidence of recent years, the ratio of units of abobotulinumtoxin A (dysport) and onabotulinumtoxin A (botox) is 3(2,5):1. Use of a fixed ratio of units is possible only when switching from one drug to another or in case of limiting access to specific drug. Botulinum toxin type A is the first line of therapy in the treatment of several neurological diseases. The most commonly used drugs of botulinum toxin type A (botox, dysport, xeomin) have a significant evidence base that confirms their efficacy and optimal safety profile. The main difference between botulinum toxin type A is their potential activity of action, i.e., activity units and total therapeutic dose.

Botulinum Toxin for Neck Rejuvenation: Assessing Efficacy and Redefining Patient Selection

BACKGROUND

The "Nefertiti lift" consists of injecting the platysmal bands and the inferior border of the mandible with botulinum toxin. No clinical trial has evaluated its effect on the different lower face and neck aging components, and little is known about the clinical characteristics that predict treatment success.

METHODS

Patients were injected with abobotulinumtoxinA along the inferior border of the mandible and into the platysmal bands. Using standardized preinjection and postinjection photographs, the jowls, marionette lines, oral commissures, neck volume, and platysmal bands at maximal contraction and at rest were assessed with validated photonumeric scales. In addition, the overall appearance of the lower face and neck was evaluated by the Investigators and Subjects Global Aesthetic Improvement Score. Pain and patient satisfaction rates were also evaluated.

RESULTS

Thirty patients were injected with a mean dose of 124.9 U of abobotulinumtoxinA per patient. Platysmal bands at rest and with maximal tension reached a statistically significant improvement. The other components showed a tendency for improvement but did not reach statistical significance; 93.3 percent of investigators and patients rated the overall results as improved, and 96.6 percent of patients were satisfied with their results. When comparing the patients who improved the most to all the other patients, they had lower preinjection region-specific scores.

CONCLUSIONS

The Nefertiti lift can be used on its own or in conjunction with other rejuvenating procedures. It is particularly helpful in younger patients with platysma muscle hyperactivity and retained skin elasticity.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Botulinum Neurotoxins: Biology, Pharmacology, and Toxicology

The study of botulinum neurotoxins (BoNT) is rapidly progressing in many aspects. Novel BoNTs are being discovered owing to next generation sequencing, but their biologic and pharmacological properties remain largely unknown. The molecular structure of the large protein complexes that the toxin forms with accessory proteins, which are included in some BoNT type A1 and B1 pharmacological preparations, have been determined. By far the largest effort has been dedicated to the testing and validation of BoNTs as therapeutic agents in an ever increasing number of applications, including pain therapy. BoNT type A1 has been also exploited in a variety of cosmetic treatments, alone or in combination with other agents, and this specific market has reached the size of the one dedicated to the treatment of medical syndromes. The pharmacological properties and mode of action of BoNTs have shed light on general principles of neuronal transport and protein-protein interactions and are stimulating basic science studies. Moreover, the wide array of BoNTs discovered and to be discovered and the production of recombinant BoNTs endowed with specific properties suggest novel uses in therapeutics with increasing disease/symptom specifity. These recent developments are reviewed here to provide an updated picture of the biologic mechanism of action of BoNTs, of their increasing use in pharmacology and in cosmetics, and of their toxicology.