title: A multicenter, double-blind, randomized, placebo-controlled study of the efficacy and safety of botulinum toxin type A in the treatment of glabellar lines.
abstract: BACKGROUND
  Botulinum toxin type A (BTX-A) is widely used for facial esthetics but is incompletely studied.
  
  
  OBJECTIVE
  This study was conducted to evaluate the efficacy and safety of BTX-A treatment of glabellar lines.
  
  
  METHODS
  Patients with moderate to severe glabellar lines at maximum frown received intramuscular injections of 20 U BTX-A (BOTOX, Allergan, Inc, Irvine, Calif) or placebo into 5 glabellar sites. Patients were followed up for 120 days after injection. Outcome measures were physician rating of glabellar line severity at maximum frown and rest, patient assessment of improvement, and vital sign and adverse event monitoring.
  
  
  RESULTS
  Two hundred sixty-four patients were enrolled (BTX-A: 203, placebo: 61). There was a significantly greater reduction in glabellar line severity with BTX-A than with placebo (all measures, every follow-up visit; P <.022). The effect was maintained for many patients through day 120. There was a low occurrence (5.4%) of mostly mild blepharoptosis in the BTX-A group.
  
  
  CONCLUSIONS
  BTX-A injections are safe and effective in reducing the severity of glabellar lines.
authors.affiliation: Vancouver Hospital, Vancouver, British Columbia, Canada.
authors.forename: J Alastair
authors.initials: JA
authors.lastname: Carruthers
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Lowe
authors.forename: M Alan
authors.initials: MA
authors.lastname: Menter
authors.forename: John
authors.initials: J
authors.lastname: Gibson
authors.forename: Marian
authors.initials: M
authors.lastname: Nordquist
authors.forename: Julie
authors.initials: J
authors.lastname: Mordaunt
authors.forename: Patricia
authors.initials: P
authors.lastname: Walker
authors.forename: Nina
authors.initials: N
authors.lastname: Eadie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D005148:Facial Dermatoses / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D005546:Forehead; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D011446:Prospective Studies; D012720:Severity of Illness Index; D015595:Skin Aging / Q000473:pathology*; D016896:Treatment Outcome; D014481:United States
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A