indication

For the treatment of patients with cervical dystonia to reduce the severity of abnormal head position and neck pain associated with cervical dystonia.

pharmacology

Botulinum Toxin Type B inhibits acetylcholine release at the neuromuscular junction via a three stage process: 1) Heavy Chain mediated neurospecific binding of the toxin, 2) internalization of the toxin by receptor-mediated endocytosis, and 3) ATP and pH dependent translocation of the Light Chain to the neuronal cytosol where it acts as a zinc-dependent endoprotease cleaving polypeptides essential for neurotransmitter release.

mechanism of action

Botulinum Toxin Type B binds to and cleaves the synaptic Vesicle Associated Membrane Protein (VAMP, also known as synaptobrevin) which is a component of the protein complex responsible for docking and fusion of the synaptic vesicle to the presynaptic membrane, a necessary step to neurotransmitter release.

toxicity

One unit of Botulinum Toxin Type B corresponds to the calculated median lethal intraperitoneal dose (LD50) in mice.

absorption

Though pharmacokinetic or ADME studies were not performed, Botulinum Toxin Type B is not expected to be present in the peripheral blood at measurable levels following IM injection at the recommended doses.