title: Unlabeled uses of botulinum toxins: a review, part 1.
abstract: OBJECTIVE
  Efficacy and safety data regarding the unlabeled uses of botulinum toxins are reviewed, and the pharmacology, adverse effects, and characteristics of commercially available botulinum toxins are discussed.
  
  
  CONCLUSIONS
  More than 300 articles have been published on the use of botulinum toxins, particularly botulinum toxin type A, to treat conditions characterized by excessive smooth or skeletal muscle spasticity. Botulinum toxins are synthesized by Clostridium botulinum and cause temporary local paralysis of the injected muscle by inhibiting acetylcholine release at the neuromuscular junction. While botulinum toxins have Food and Drug Administration-approved labeling to treat a limited number of spasticity disorders, including cervical dystonia and blepharospasm, the toxins have more than 50 reported therapeutic uses. Among these uses, the most rigorously studied indications include achalasia, essential tremors, palmar hyperhidrosis, chronic anal fissures, headache prophylaxis, and limb spasticity. The main adverse effects of the toxins are pain and erythema at the injection site, although unintended paralysis of muscles adjacent to the site of toxin injection may also occur.
  
  
  CONCLUSIONS
  Clinical studies support the use of botulinum toxins for certain conditions, although more studies are needed to establish the role of the drug relative to conventional therapies and to determine patient predictors of response. Although botulinum toxins are generally well tolerated, a patient-specific risk-benefit assessment should precede any decision to use them for unlabeled indications.
authors.affiliation: Drug Information and Analysis Service, University of California at San Francisco, San Francisco, CA 94143, USA. chengc@pharmacy.ucsf.edu
authors.forename: Christine M
authors.initials: CM
authors.lastname: Cheng
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Chen
authors.forename: Rosalie P
authors.initials: RP
authors.lastname: Patel
mesh_terms: D001905:Botulinum Toxins / Q000627:therapeutic use*; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D017277:Drug Approval; D004348:Drug Labeling; D006801:Humans; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D009465:Neuromuscular Agents; C096323:rimabotulinumtoxinB; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A