title: A double-blind, randomized, placebo-controlled, two-dose comparative study of botulinum toxin type A for treating glabellar lines in Japanese subjects.
abstract: BACKGROUND
  Systematic, well-controlled clinical trials of botulinum toxin type A (BoNTA) in diverse patient populations are needed. The aim of this study was to characterize the safety and efficacy of 10-U and 20-U BoNTA doses versus placebo for treating glabellar lines in Japanese subjects.
  
  
  METHODS
  A 16-week, multicenter, double-blind, randomized, placebo-controlled trial comparing 10 or 20 U of BoNTA versus placebo in 142 Japanese subjects with glabellar lines of at least moderate severity at maximal contraction. The primary efficacy endpoint was physician-rated line severity at maximal contraction 4 weeks after treatment. Secondary efficacy endpoints included physician/subject ratings and estimates of the effect's duration.
  
  
  RESULTS
  Response rates by physician-rated line severity at maximal contraction (week 4) were 86.4% (10 U), 88.6% (20 U), and 0% (placebo, p < 0.001). Line severity at maximal contraction in each BoNTA group (p < 0.001) improved significantly from baseline at each visit. BoNTA and placebo differed significantly on all other efficacy measures. Mean duration of effect was 9.4 weeks in the 20-U group and 7.9 weeks in the 10-U BoNTA group. No serious adverse events occurred.
  
  
  CONCLUSIONS
  Doses of BoNTA of 10 and 20 U are effective and safe for treating glabellar lines in Japanese subjects, and the 20-U dose provides greater efficacy and longer duration of effect.
authors.affiliation: Department of Plastic and Reconstructive Surgery, School of Medicine, Kyorin University, Mitaka-shi, Tokyo, Japan. harii@kyorin-u.ac.jp
authors.forename: Kiyonori
authors.initials: K
authors.lastname: Harii
authors.forename: Makoto
authors.initials: M
authors.lastname: Kawashima
mesh_terms: D000328:Adult; D044466:Asian People; D019274:Botulinum Toxins, Type A / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007279:Injections, Subcutaneous; D007564:Japan; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011336:Probability; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors; D015595:Skin Aging / Q000187:drug effects* / Q000208:ethnology*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019274:Botulinum Toxins, Type A