The toxin itself is released from the bacterium as a single chain, then becomes activated when cleaved by its own proteases. The active form consists of a two-chain protein composed of a 100-kDa heavy chain polypeptide joined via disulfide bond to a 50-kDa light chain polypeptide. The heavy chain contains domains with several functions: it has the domain responsible for binding specifically to presynaptic nerve terminals, as well as the domain responsible for mediating translocation of the light chain into the cell cytoplasm as the vacuole acidifies. The light chain is a zinc metalloprotease and is the active part of the toxin. It is translocated into the host cell cytoplasm where it cleaves the host protein SNAP-25, a member of the SNARE protein family which is responsible for fusion. The cleaved SNAP-25 is unable to mediate fusion of vesicles with the host cell membrane, thus preventing the release of the neurotransmitter acetylcholine from axon endings. This blockage is slowly reversed as the toxin loses activity and the SNARE proteins are slowly regenerated by the affected cell.
The safety and effectiveness for the treatment of anatomic regions other than the mid-face with JUVÉDERM VOLUMA® XC; facial wrinkles and folds with JUVÉDERM® Ultra XC, JUVÉDERM® Ultra Plus XC, and JUVÉDERM VOLLURE™ XC; and the lips and perioral area with JUVÉDERM® Ultra XC and JUVÉDERM VOLBELLA® XC have not been established in controlled clinical studies
In clinical trials, 6.5% of patients (36/552) initiated clean intermittent catheterization for urinary retention following treatment with BOTOX® 100 Units as compared to 0.4% of patients (2/542) treated with placebo. The median duration of catheterization for patients treated with BOTOX® 100 Units was 63 days (minimum 1 day to maximum 214 days) as compared to a median duration 11 days (minimum 3 days to maximum 18 days) for patients receiving placebo.
Ptosis generally occurs from injecting the frontalis incorrectly. The worst mistake is for the injector to move the procerus and corrugator injection points higher, where they will place more onabotulinumtoxinA into the frontalis. It is important to examine patients to determine their preexisting conditions prior to treatment administration. In particular, patients should be examined for pre-existing eyelid ptosis or pseudoptosis. With pseudoptosis, the lid strength is normal, but soft tissue covers part of the upper lid. With lid ptosis, the lid strength is weak. For both lid ptosis and pseudoptosis, patients will have frontalis compensatory activity, resulting in upgoing eyebrows (reverse Babinski sign). With brow ptosis, the frontalis is weak, and the eyebrow is depressed downward leading to tissue resting on the upper lid. To avoid this, the frontalis should be injected in the upper third of the forehead. The corrugator muscle attaches to bone at the medial end of the superciliary arch. The muscle fibers travel laterally and upward inserting into the skin in the middle of the supraorbital margin. The corrugator muscle is partially blended with the orbicularis oculi and occipitofrontalis. The supraorbital and supratrochlear nerves pass through the corrugator muscle. The corrugator muscle acts to pull the eyebrows downward and medially, which causes vertical wrinkle lines in the skin between the brows.
Two preparations of botulinum antitoxins are available for treatment of botulism. Trivalent (A,B,E) botulinum antitoxin is derived from equine sources using whole antibodies. The second antitoxin is Heptavalent (A,B,C,D,E,F,G) botulinum antitoxin, which is derived from equine antibodies which have been altered to make them less immunogenic. This antitoxin is effective against all known strains of botulism.
It is not known whether BOTOX® is safe or effective to treat increased stiffness in upper limb muscles other than those in the elbow, wrist, fingers, and thumb, or in lower limb muscles other than those in the ankle and toes. BOTOX® has not been shown to help people perform task-specific functions with upper limbs or increase movement in joints that are permanently fixed in position by stiff muscles. BOTOX® is not meant to replace existing physical therapy or other rehabilitation that may have been prescribed.