Pharmacology of botulinum toxin

Long-term efficacy of botulinum toxin A for treatment of blepharospasm, hemifacial spasm, and spastic entropion: a multicentre study using two drug-dose escalation indexes

“…6 Botulinum neurotoxin A (BoNT-A) therapy for strabismus was introduced by Scott 11 in the early 1980s, and in 1989 the Food and Drug Administration approved BoNT-A for ophthalmologic and neurologic use in treating strabismus, blepharospasm, and hemifacial spasm (HFS). 12 Since then, BoNT-A has replaced eyelid surgery as the first-line therapy for BEB, [13][14][15][16][17] and has become the treatment of choice, as it is very successful in controlling eyelid spasms. [17][18][19][20][21][22][23][24][25][26][27][28][29] Although some authors have reported decreasing effectiveness with prolonged use, 23,30 others have not observed this in the majority of patients.…”

Aesthetic Medicine―A Separate Field of Medicine, as a Combination of Many Medical Specialties

“…These treatments, by inhibiting secretion of ACh, also lead to a blockage of the sympathetic innervation of sweat glands-causing inhibition of excessive sweating. TXB-A blocks the release of ACh from presynaptic nerve endings, because it contains tin endopeptidase, which is responsible for the distribution of SNAP-25 protein, necessary to the process of exocytosis of the synaptic vesicles containing ACh (from the presynaptic part to the postsynaptic part) [14]. In this situation, these treatments are the closest combined with neurology because of the inhibition of secretion of Ach from the presynaptic nerve endings, or orthopedics, because the TXB-A is introduced deep into the muscles in order to eliminate wrinkles, bruxism, gummy smile, platysmal neck bands, downturn of corners of the mouth, etc.…”

Qualidade de vida e custos diretos em pacientes com blefaroespasmo essencial e espasmo hemifacial, tratados com toxina botulínica-A

“…A toxina botulínica é o tratamento de escolha para ambas as doenças (1)(2)(3)(4)(5)(6)(7) . Esta neurotoxina é produzida pela bactéria Clostridium botulinum e atua bloqueando a liberação da acetilcolina na junção neuro-muscular, levando à paralisia muscular, que permanece por vários meses, proporcionando benefí-cios clínicos significantes (10)(11) . Esse efeito foi inicialmente observado em músculos extra-oculares de macacos (12) .…”

“…Os pacientes com EH experimentam um efeito mais prolongado, ao redor de 4 a 6 meses (1,3,(5)(6)(7)(8) . (2,(10)(11) . Em 1989, a droga foi liberada pelo FDA (Food and Drug Administration) para tratamento de estrabismo e blefaroespasmo essencial (11) .…”