Cosmetic uses of botulinum toxin type B

The use of botulinum toxin for the treatment of hyperfunctional facial muscles has become one of the most successful and popular cosmetic therapies in the dermatologist's repertoire. Until very recently, the only form available was botulinum toxin A, which is marketed under the name Botox®. A new form of botulinum toxin, Myobloc™, has just become available. This medication is a stable complex of botulinum toxin B. It comes as a liquid and is stable at room temperature for at least 9 months and with refrigeration for up to 30 months without significant loss of activity. Predinical animal studies indicate that appropriate doses induce equivalent paralysis as with botulinum toxin A, and it appears to spread less to adjacent muscles. It is FDA approved for human use in the treatment of cervical dystonia. For this indication, it is equally as effective as botulinum toxin A, with a similar safety profile and a slightly longer duration of action. Investigations for the cosmetic use of Myobloc are just beginning, with dosing and safety information yet to be elucidated.