title: Safety and efficacy of multiuse botulinum toxin vials for intralaryngeal injection.
abstract: OBJECTIVE
  Centers for Disease Control and Prevention guidelines maintain that single-use vials cannot be used for multiple patients. Botox product labeling states that the reconstituted toxin should be used within 4 hours on a single patient based on concerns of reduced potency, contamination, and consequent infections. The purpose of this study was to determine the safety and efficacy of using single-use vials in a multidose fashion.
  
  
  METHODS
  Prospective study and cohort chart review.
  
  
  METHODS
  A multi-institutional three-part study was performed between May 2013 and October 2013: 1) a summation of subjects' recall of their past experiences (symptoms/response) with previous multidose Botox injections, 2) a prospective study of intralaryngeal injections, and 3) a chart review of injection responses in a subset of the cohort.
  
  
  RESULTS
  Seven hundred forty-three subjects receiving 6,216 injections demonstrated zero infection-related complications on retrospective chart review. One hundred seventy-nine subjects recalled 24.0% overall adverse events, 10.6% redness, 7.3% pain and swelling at the injection site, and 0% fever. One hundred seventy-four subjects prospectively reported 12.6% overall adverse events. The self-reported efficacy rate of Botox injection was 96.6%.
  
  
  CONCLUSIONS
  The low rates of adverse events following the use of Botox in a multipatient fashion are consistent with other percutaneous injections. No evidence of infection was found with multidose Botox use. Given the low incidence of side effects and high success rate, Botox can be used both safely and effectively in a multipatient fashion.
  
  
  METHODS
  4
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Emily M
authors.initials: EM
authors.lastname: Barrow
authors.forename: Clark A
authors.initials: CA
authors.lastname: Rosen
authors.forename: Edie R
authors.initials: ER
authors.lastname: Hapner
authors.forename: Sarah
authors.initials: S
authors.lastname: Smith
authors.forename: Jeanne L
authors.initials: JL
authors.lastname: Hatcher
authors.forename: Blake
authors.initials: B
authors.lastname: Simpson
authors.forename: Michael M
authors.initials: MM
authors.lastname: Johns
mesh_terms: D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D055154:Dysphonia / Q000188:drug therapy* / Q000503:physiopathology; D005500:Follow-Up Studies; D006801:Humans; D007267:Injections; D007830:Larynx; D009465:Neuromuscular Agents / Q000008:administration & dosage; D011446:Prospective Studies; D016896:Treatment Outcome; D014833:Voice Quality / Q000187:drug effects*
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
keywords: Botox; botulinum toxin; efficacy; larynx; multidose; safety; voice