Evidence-based review of current botulinum toxin treatment indications in medicine

Botulinum neurotoxin (BoNT) has been increasingly used not only as a cosmetic drug but, more importantly, it has emerged as the most versatile therapeutic, utilized in virtually all sub-specialties of medicine. In neurology, there is Level A (effective) evidence for the use of certain serotypes of BoNT in cervical dystonia, chronic migraines, upper- and lower-limb spasticity and Level B (probably effective) evidence in blepharospasm. These levels of recommendation, however, must be interpreted cautiously as they are based only on published randomized, controlled studies and are limited to particular products. United States Food and Drug Administration (US-FDA) approved BoNT for these and other indications, such as focal axillary hyperhidrosis and sialorrhea, but there are a growing number of conditions for which BoNT is used off-label. In addition to focal dystonia, BoNT is also increasingly used to treat tremor and other movement disorders and a variety of neuropathic pain disorders including trigeminal neuralgia, post-herpetic neuralgia, and diabetic neuropathy. In urology, there are several randomized controlled trials supporting the benefits of BoNT in overactive bladder and interstitial cystitis. In gastroenterology, BoNT is used to treat anal fissures and achalasia. Thus, BoNT is the most widely used therapeutic molecule.