Therapeutic Use of Botulinum Toxins: Background and History

Abstract

The seven botulinum neurotoxin serotypes share less than 50% sequence homology and are immunologically distinct. The neurotoxins inhibit release of the neurotransmitter acetylcholine from the axon terminals of motor neurons, preganglionic sympathetic and parasympathetic neurons, and postganglionic parasympathetic nerves by a multi-step mechanism that differs slightly, but significantly, for each serotype. The inhibition is long lasting but temporary. The resulting muscle paralysis has provided the basis for therapeutic use of botulinum toxin types A and B in a variety of focal dystonias. The safety of the botulinum toxins, when administered focally, has permitted their widespread use in a number of other painful conditions.

Differences between motor point and innervation zone locations in the biceps brachii. An exploratory consideration for the treatment of spasticity with botulinum toxin

“…This toxin blocks the release of acetylcholine at the axon terminal (Setler, 2002) Its intramuscular application has proven to be relatively safe (Bakheit, 2006), but it is not free of adverse effects, such as blocking of autonomic nerves, muscle atrophy by anatomical denervation and immunological reactions (Simpson et al, 2009;Dressler and Hallett, 2006) The occurrence of side effects is dependent on the delivered dose of toxin (Borodic et al, 1990;Eleopra et al, 1996). It has been clinically shown that injection of a minimum effective dose reduces the presence of adverse effects (Brans et al, 1995).…”

Effects of botulinum a toxin injection on the extraocular muscle fiber layers: Comparison between subtenon injection and intramuscular injection

“…Botulinum A toxin is known to exert its effect by reducing the rate of supply of readily releasable neurotransmitters. 8,16,17 This chemical denervation results in the atrophy of the affected muscle. This chemodenervation effect is temporary, so the safety and convenience of botulinum A toxin enable it to be used for various conditions.…”

The Medicinal Chemistry of Botulinum, Ricin and Anthrax Toxins

“…Additionally, sub-optimal environmental [24,25] and complications [26] associated with their use may factors such as temperature, humidity, and wind will be found be found in the literature, denature these proteins, thereby reducing their effectiveness. Exposure to air, or direct sunlight, will denature the toxin As Biological Warfare Agents within a few hours, rendering it biologically inactive [3].…”