Botulinum toxin type B (MYOBLOC) versus botulinum toxin type A (BOTOX) frontalis study: rate of onset and radius of diffusion

Cosmetic Considerations in Dark-Skinned Patients

For dermatologists, diversities of human races result in an opportunity to encounter patients with various skin types. Cosmetic procedures have gained more popularity and become more accessible over the past decades. Thus, the selection of appropriate treatment protocol for each patient becomes inevitable. This review will focus on basic knowledge and key points in performing safe cosmetic-related procedures in patients with dark-complexioned skin. In terms of structure and function of the skin, people of color have equal epidermal thickness, corneocyte size and melanocyte number. However, they have more stratum corneum compaction, melanosome dispersion and melanocyte activity than fair skin individuals. Data regarding drug penetration and cutaneous irritation showed conflicting results. Superficial chemical peels and microdermabrasion can be done safely in dark-skinned patients. Medium-depth peel should be used with extreme caution. While deep-depth peel should be avoided at all times due to pigmentary and textural complications. Prolonged treatment interval, use of priming agents and sun protection are recommended. Injectable materials including botulinum toxin and soft tissue augmentation by hyaluronic acid filler can be done harmlessly in dark-skinned patients. Lasers and energy-based devices should be done with caution. Higher melanin dispersion and melanocyte activity acts as competitive chromophore. Pigmentary or textural changes can occur after aggressive treatment protocol. High energy setting, pulse stacking, short wavelength lasers and short treatment interval should be avoided in dark-skinned patients.

Botulinum Toxin A for the Treatment of Sympathomimetic Pressor-Induced Digital Hand Ischemia in the Critically Ill Intensive Care Unit Patient

Vasopressor-induced ischemia of the hand, while relatively rare, is a severe complication in critically ill intensive care unit (ICU) patients requiring high concentrations of sympathomimetic pressors and often results in digit necrosis and amputation. Currently, there are no widely accepted approaches for treating this cause of peripheral digital ischemia. Case reports have demonstrated that reducing the concentration of vasopressors that patients are given may reverse the progression of ischemic events prior to necrosis. While this approach is at odds with the principle of "life over limb," it demonstrates that digit necrosis can be reversed, resulting in improved outcomes. Here, we present a therapeutic strategy for treating digital limb ischemia in the septic ICU patient without the need to lower systemic vasopressor dose by using locally injected botulinum toxin A into ischemic hands.

A Phase 3, Randomized, Multi-center Clinical Trial to Evaluate the Efficacy and Safety of Neu-BoNT/A in Treatment of Primary Axillary Hyperhidrosis

BACKGROUND

Botulinum toxin type A is widely used to treat primary axillary hyperhidrosis and has proven to be an effective and safe approach. Onabotulinumtoxin A was approved by the FDA as a treatment for primary axillary hyperhidrosis. This study aimed to evaluate the efficacy and safety of Neu-BoNT/A in subjects diagnosed with primary axillary hyperhidrosis.

METHODS

The Hyperhidrosis Disease Severity Scale, gravimetric measurement of sweat, and Global Assessment Scale were analyzed at weeks 4, 8, 12, and 16 to determine the effect of treatment. Adverse events, physical examination, and vital signs were monitored.

RESULTS

Subjects treated with Neu-BoNT/A showed statistically significant improvement by all 3 methods at weeks 4, 8, 12, and 16 (P value = 0.00). There were no severe adverse events or significant changes in vital signs, physical examination, or laboratory tests.

CONCLUSION

Neu-BoNT/A can be effectively and safely used for primary axillary hyperhidrosis.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Long-lasting attenuation of amygdala-kindled seizures after convection-enhanced delivery of botulinum neurotoxins a and B into the amygdala in rats

Botulinum neurotoxins (BoNTs) are well recognized to cause potent, selective, and long-lasting neuroparalytic actions by blocking cholinergic neurotransmission to muscles and glands. There is evidence that BoNT isoforms can also inhibit neurotransmission in the brain. In this study, we examined whether locally delivered BoNT/A and BoNT/B can attenuate kindling measures in amygdala-kindled rats. Male rats were implanted with a combination infusion cannula-stimulating electrode assembly into the right basolateral amygdala. Fully kindled animals received a single infusion of vehicle or BoNT/A or BoNT/B at doses of 1, 3.2, or 10 ng over a 20-minute period by convection-enhanced delivery. Electrographic (EEG) and behavioral kindling measures were determined at selected times during the 3- to 64-day period after the infusion. BoNT/B produced a dose-dependent elevation in after-discharge threshold and duration and a reduction in the seizure stage and duration of behavioral seizures that lasted for up to 50 days after infusion. BoNT/A had similar effects on EEG measures; behavioral seizure measures were also reduced, but the effect did not reach statistical significance. The effects of both toxins on EEG and behavioral measures progressively resolved during the latter half of the observation period. Animals gained weight normally, maintained normal body temperature, and did not show altered behavior. This study demonstrates for the first time that locally delivered BoNTs can produce prolonged inhibition of brain excitability, indicating that they could be useful for the treatment of brain disorders, including epilepsy, that would benefit from long-lasting suppression of neurotransmission within a circumscribed brain region.

Diffusion of botulinum toxins

BACKGROUND

It is generally agreed that diffusion of botulinum toxin occurs, but the extent of the spread and its clinical importance are disputed. Many factors have been suggested to play a role but which have the most clinical relevance is a subject of much discussion.

METHODS

This review discusses the variables affecting diffusion, including protein composition and molecular size as well as injection factors (e.g., volume, dose, injection method). It also discusses data on diffusion from comparative studies in animal models and human clinical trials that illustrate differences between the available botulinum toxin products (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB).

RESULTS

Neither molecular weight nor the presence of complexing proteins appears to affect diffusion; however, injection volume, concentration, and dose all play roles and are modifiable. Both animal and human studies show that botulinum toxin products are not interchangeable, and that some products are associated with greater diffusion and higher rates of diffusion-related adverse events than others.

DISCUSSION

Each of the botulinum toxins is a unique pharmacologic entity. A working knowledge of the different serotypes is essential to avoid unwanted diffusion-related adverse events. In addition, clinicians should be aware that the factors influencing diffusion may range from properties intrinsic to the drug to accurate muscle selection as well as dilution, volume, and dose injected.

Botulinum neurotoxin A: a review

Despite its ubiquity in cosmetic circles and broad general awareness, a literature search of botulinum neurotoxin in JPRAS and BJPS yielded a mere 4 articles germane to cosmesis. A pair each detailing its application in masseteric hypertrophy(1,2) and the use of cryoanalgesia.(3,4) Given that botulinum neurotoxin A is the most commonly used cosmetic treatment, with American figures being most accurate,(5) a review of the background, development and scientific evidence would be perhaps useful, if not overdue, as Plastic Surgeons increasingly incorporate non-surgical interventions into their practices as part of a comprehensive facial rejuvenation strategy.

Antibody-induced secondary treatment failure in a patient treated with botulinum toxin type A for glabellar frown lines

Botulinum toxin type A (BTX-A) preparations are widely used nonsurgical treatments for facial wrinkles. Higher doses of BTX-A are also used for therapeutic purposes in the treatment of conditions involving increased muscle tone, such as cervical dystonia. The phenomenon of antibody-induced treatment failure is well known in the therapeutic setting, but reports are also emerging following cosmetic use of BTX-A. We describe the case of a 41-year-old female nurse who developed secondary treatment failure during 6 years of BTX-A treatment for glabellar lines. After a good response to the first BTX-A injection, the intensity and duration of effect decreased after subsequent treatments. Antibody tests revealed a high titer of neutralizing anti-BTX-A antibodies. This case shows secondary treatment failure due to the production of neutralizing antibodies following administration of BTX-A formulations for cosmetic purposes and demonstrates that immunogenicity of BTX-A preparations is an important consideration, even in the cosmetic setting.

Botulinum toxin in facial rejuvenation: an update

Since its initial approval by the US Food and Drug Administration (FDA) 20 years ago for the treatment of strabismus, hemifacial spasm, and blepharospasm in adults, botulinum toxin (BTX) has become one of the most frequently requested products in cosmetic rejuvenation around the world. After years of clinical success and consistent safety in the upper face, the use of BTX has expanded and evolved to include increasingly complicated indications. In the hands of adept injectors, the focus has shifted from the treatment of individual dynamic rhytides to shaping, contouring, and sculpting, alone or in combination with other cosmetic procedures, to enhance the aesthetic appearance of the face. Although recent reports have questioned the safety of BTX, 25 years of therapeutic and over 20 years of cosmetic use has demonstrated an impressive record of safety and efficacy when used appropriately by experienced injectors.

Treating glabellar lines with botulinum toxin type A-hemagglutinin complex: a review of the science, the clinical data, and patient satisfaction

Botulinum toxin type A treatment is the foundation of minimally invasive aesthetic facial procedures. Clinicians and their patients recognize the important role, both negative and positive, that facial expression, particularly the glabellar frown lines, plays in self-perception, emotional well-being, and perception by others. This article provides up-to-date information on fundamental properties and mechanisms of action of the major approved formulations of botulinum toxin type A, summarizes recent changes in naming conventions (nonproprietary names) mandated by the United States Food and Drug Administration, and describes the reasons for these changes. The request for these changes provides recognition that formulations of botulinum toxins (eg, onabotulinumtoxinA and abobotulinumtoxinA) are not interchangeable and that dosing recommendations cannot be based on any one single conversion ratio. The extensive safety, tolerability, and efficacy data are summarized in detail, including the patient-reported outcomes that contribute to overall patient satisfaction and probability treatment continuation. Based on this in-depth review, the authors conclude that botulinum toxin type A treatment remains a cornerstone of facial aesthetic treatments, and clinicians must realize that techniques and dosing from one formulation cannot be applied to others, that each patient should undergo a full aesthetic evaluation, and that products and procedures must be selected in the context of individual needs and goals.

Botulinum toxin: description of injection techniques and examination of controversies surrounding toxin diffusion

The benefits derived from botulinum toxin (BTX) injections may be negated by unintentional weakness of adjacent uninjected muscles. Such weakness may be the result of inaccurate targeting, or diffusion of BTX to surrounding muscles. Several techniques, using electromyographic, endoscopic or imaging guidance are purported to increase the accuracy of targeting. Diffusion of BTX is thought to be influenced by factors such as dose, concentration, injectate volume, number of injections, site and rate of injection, needle gauge, muscle size, muscular fascia, distance of needle tip from the neuromuscular junction, and protein content of the BTX formulation. This article describes techniques that aim to increase the accuracy of BTX injections and examines the controversies surrounding diffusion of BTX following injection.

Botulinum neurotoxins: fundamentals for the facial plastic surgeon

The most commonly performed nonsurgical cosmetic procedure in the facial plastic surgery armamentarium involves the various commercial preparations of botulinum neurotoxins. These drugs have undergone a transformation from public health scourge to near ubiquitous therapeutic modality across the entire medical spectrum. Herein, the history of botulinum neurotoxins is reviewed, including an exploration of their pharmacology, neuromuscular junction physiology, a description of the commercially available preparations, and the recent research concerning the practicalities of their clinical use.

Pilot study comparing the diffusion of two formulations of botulinum toxin type A in patients with forehead hyperhidrosis

BACKGROUND

Different formulations of botulinum toxin type A (BoNTA) may have different diffusion characteristics.

OBJECTIVE

The objective was to compare the diffusion characteristics of two formulations of BoNTA.

MATERIALS AND METHODS

A total of 20 patients with forehead hyperhidrosis received four injections of BoNTA in their forehead (one medial and lateral injection of one formulation randomly assigned to one forehead side, one medial and lateral injection of the other formulation to the other forehead side). Patients received 3 U/injection of BoNTA(1) (BOTOX, Allergan, Inc.) and were randomly assigned to receive BoNTA(2) (Dysport, Ipsen Ltd.) at a dose ratio of 1:2.5, 1:3, or 1:4. The area of anhidrosis was highlighted using iodine and starch and determined by software from standardized photography.

RESULTS

During the 6 months after treatment, the area of anhidrosis was larger with BoNTA(2) in 93% (195/210) of medial-medial or lateral-lateral comparisons of the two products and at all dose ratios. The smaller area of anhidrosis with BoNTA(1) did not compromise its efficacy in inhibiting contraction of frontalis muscle.

CONCLUSION

BoNTA(2) has a greater area of diffusion in the forehead than BoNTA(1), even with identical injection volumes. This may hinder accurate localization of clinical effect, thereby increasing the potential for adverse effects.

Botulinum Toxins for Facial Wrinkles: Beyond Glabellar Lines

Botulinum toxin type A (BTX-A) has been used for years with excellent results for upper facial cosmetic applications. Because of this success, the use of BOX-A for facial aesthetics has expanded to the lower facial and neck regions. BTX-A, especially when used in combination with fillers, has generally proven to be safe and efficacious in these areas. For optimal results, however, several issues must be taken into considerations, including dosing differences versus upper facial applications, the specific type of botulinum toxin used and the importance of precise placement and injection technique. In this article, the authors present their experience with BTX-A in the lower face and neck, and compare and contrast their current practices with those reported by others.

Dose-Finding, Safety, and Tolerability Study of Botulinum Toxin Type B for the Treatment of Hyperfunctional Glabellar Lines

BACKGROUND

Previous open-label studies have demonstrated that botulinum toxin type B (BTX-B, Myobloc, Solstice Neurosciences) in doses of up to 3,000 U is safe and effective in the treatment of glabellar wrinkles.

OBJECTIVE

This double-blind, randomized, placebo-controlled, sequential-dose-escalation study evaluated the safety and tolerability of seven BTX-B doses ranging from 250 to 3,000 U in the treatment of subjects with hyperfunctional glabellar lines.

METHODS

Participants received a single intramuscular treatment of either BTX-B or placebo at five facial sites with a 12-week follow-up period. Primary efficacy outcome measure was the Investigator Global Scale score of subject's glabellar lines at rest and at full frown. Safety was evaluated primarily on the occurrence of adverse events (AEs).

RESULTS

The investigator scores demonstrated a statistically significant increasing dose-response trend in the percentage of subjects with no lines or mild lines at rest from Weeks 1 to 12 (p=.0420) and at full frown from Weeks 1 to 8 (p<.0001). Fifty-one subjects (36.7%) experienced AEs; the most common AE was headache not otherwise specified, experienced by 19 subjects (13.7%).

CONCLUSIONS

BTX-B at doses up to 3,000 U was safe and well tolerated in the treatment of hyperfunctional glabellar lines. Treatment with BTX-B reduced hyperfunctional glabellar lines in subjects, and the duration of action appeared to be related to the dose administered. Further studies using higher doses of BTX-B for treatment of glabellar wrinkles are planned.

Update on Botulinum Toxin

Botulinum toxin for facial enhancement is currently the most popular aesthetic procedure performed in the United States. New developments have occurred within the last few years. Patients prefer having multiple areas of the upper face treated which increases patient satisfaction. Treatment of the forehead is now being accomplished with fewer units of botulinum toxin. This helps preserve the natural look of some movement of the forehead. Men require more units of botulinum toxin than women. Combination therapy using botulinum toxin along with lasers or filler substances is ideal. Aesthetic medicine knowledge has progressed, contributing a greater understanding of botulinum treatment for advanced areas of the face. The orbicularis oris, mentalis, and depressor anguli oris are now routinely treated and help improve overall facial appearance. Other forms of botulinum toxins (additional type A or type B toxins) are available, each with advantages and disadvantages.

Botulinum toxin A (Botox) and sweating-dose efficacy and comparison to other BoNT preparations

BACKGROUND

Botulinum toxin type A (BoNT/A) is 20-50 times more effective than Botulinum toxin type B (BoNT/B) concerning the treatment of muscular hypercontractions [Sloop, R.R., Cole, B.A., Escutin, R.O., 1997. Human response to botulinum toxin injection: type B compared with type A. Neurology 49, 189-194]. Botulinum toxins block motor nerves as well as autonomic fibres [Rand, M.J., Whaler, B.C., 1965. Impairment of sympathetic transmission by botulinum toxin. Nature 206, 588-591].

OBJECTIVE

Purpose of this study was to analyse the dose dependent reduction of sweating using the BoNT/A preparation Botox and to compare the results with our earlier results analysing Dysport [Braune, C., Erbguth, F., Birklein, F., 2001. Dose thresholds and duration of the local anhidrotic effect of botulinum toxin injections: measured by sudometry. Br. J. Dermatol. 144, 111-117] and Neurobloc (BoNT/B) [Birklein, F., Eisenbarth, G., Erbguth, F., Winterholler, M., 2003. Botulinum toxin type B blocks sudomotor function effectively: a 6 month follow up. J. Invest. Dermatol. 121, 1312-1316].

METHODS

Different doses of Botox were injected subcutaneously (n=27 healthy subjects). Planimetrical analyses of the area of anhidrosis and quantitative sudomotor-axon-reflex testing (QSART) were done after 3 weeks, 3 and 6 months.

RESULTS

A threshold dose of 1.25 MU Botox led to anhidrotic skin spots after 3 weeks. The duration of anhidrosis was prolonged for 3 months when 17.5 MU and for 6 months when 50 MU were injected. Anhidrotic area size decreased with time (p=0.001), indicating partial recovery at the edges. After 3 weeks, QSART had significantly decreased to 29% of baseline. With doses of 70 MU or more it decreased to zero. After 3 months, QSART had returned to 68% of baseline and after 6 months to 87%.

CONCLUSIONS

Botox dose-dependently suppressed sweating. Comparison to Dysport and Neurobloc revealed a strikingly similar efficacy after 3 weeks and 3 months for all preparations. BoNT/A in general induced a more sustained anhidrosis than BoNT/B.

Consensus recommendations on the use of botulinum toxin type a in facial aesthetics

The use of botulinum toxin type A for facial enhancement is the most common cosmetic procedure currently undertaken in the United States. Overall clinical and study experience with botulinum toxin type A treatment for facial enhancement has confirmed that it is effective and safe in both the short and long term. Nevertheless, consistent guidelines representing the consensus of experts for aesthetic treatments of areas other than glabellar lines have not been published. Therefore, a panel of experts on the aesthetic uses of Botox Cosmetic (botulinum toxin type A; Allergan, Inc., Irvine, Calif.) was convened to develop consensus guidelines. This publication comprises the recommendations of this panel and provides guidelines on general issues, such as the importance of the aesthetic evaluation and individualization of treatment, reconstitution and handling of the botulinum toxin type A, procedural considerations, dosing and injection-site variables, and patient selection and counseling. In addition, specific considerations and recommendations are provided by treatment area, including glabellar lines, horizontal forehead lines, "crow's feet," "bunny lines" (downward radiating lines on the sides of nose), the perioral area, the dimpled chin, and platysmal bands. The review of each area encompasses the relevant anatomy, specifics on injection locations and techniques, starting doses (total and per injection point), the influence of other variables, such as gender, and assessment and retreatment issues. Factors unique to each area are presented, and the discussion of each treatment area concludes with a review of key elements that can increase the likelihood of a successful outcome. Summary tables are provided throughout.

Myobloc

Myobloc is the currently available commercial formulation of type B botulinum toxin. Released in the United States in 2000, it is approved by the Food and Drug Administration for the treatment of cervical dystonia. The most commonly used botulinum toxins, the type A toxins (Botox and Dysport), affect the SNAP-25 protein, whereas the type B toxin (Myobloc) affects vesicle-associated membrane protein, also known as synaptobrevin. Both type B and type A are antigenically distinct. This article explains the difference between Myobloc and type A toxins, reviews equivalency and other published studies, and describes practical uses for this product in facial aesthetics.

Botulinum toxin types A and B: comparison of efficacy, duration, and dose-ranging studies for the treatment of facial rhytides and hyperhidrosis

One of the most common etiologic forces for the persistence of facial rhytides is the repetitive contraction of the intrinsic muscles that are necessary for facial expression. These include the forehead lines, crow's feet, glabellar rhytides, and wrinkles in the lower face. Although filling agents such as collagen and laser procedures can help reduce the appearance of these lines, they do not address the underlying forces that cause these wrinkles to persist. Botulinum toxin type-A and type-B are neurotoxins that address these issues and result in the relaxation of the intrinsic facial muscles and subsequent resolution of these dynamic facial rhytides. This article will compare the efficacy, duration, dose ranging studies, and safety in the treatment of facial rhytides with both types of toxins. In addition, the treatment of hyperhidrosis with type-A and type-B botulinum toxin will also be discussed.

Periocular botulinum toxin

Botulinum toxin type A (BOTOX, Dysport) has revolutionized treatment of wrinkles around the eyes. Since the first publications of its cosmetic benefit by Drs. Jean and Alastair Carruthers, hundreds of articles have been published about its cosmetic use. BOTOX holds U.S. Food and Drug Administration approval in the United States for treatment of glabellar lines. BOTOX is in widespread use worldwide and is currently the most popular cosmetic treatment in the United States.