title: Optimal dosage of botulinum toxin type A for treatment of glabellar frown lines: efficacy and safety in a clinical trial.
abstract: BACKGROUND
  Various preparations of botulinum toxin type A (BTX-A) are used to reduces glabellar (frown) lines. However, dose-related safety and efficacy of intramuscular injections of a widely used, locally produced BTX-A in China has not been established.
  
  
  OBJECTIVE
  Assessment of dose-dependent safety and efficacy of Chinese botulinum toxin type A (Hengli BTX-A [HBTX-A]) intramuscular injections on glabellar lines.
  
  
  METHODS
  Four hundred eighty-eight BTX-A-naive participants were included in the double-blind trial and randomly divided into placebo (n = 122), low-dose (n = 183), and high-dose (n = 183) treatment groups for injection with saline solution, 10 units and 20 units of HBTX-A, respectively, at 4 sites in the corrugator muscle and 1 site in the procerus muscle. Outcomes were recorded before treatment and after 7, 30, 60, and 120 days, including glabellar line severity at maximum contraction and relaxation.
  
  
  RESULTS
  Significantly greater improvement was observed in both HBTX-A groups in comparison with the placebo group (p < .05). Better efficacy was obtained in the high-dose treatment group. More participants developed adverse events after treatment with HBTX-A doses, than with the placebo (p < .05).
  
  
  CONCLUSIONS
  Twenty-unit HBTX-A provided optimal improvement in glabellar lines, and its use might minimize injection frequency while maintaining acceptable safety.
authors.affiliation: *Department of Dermatology, General Hospital of PLA, Beijing, China; †Department of Dermatology, Peking Union Medical College Hospital (PUMCH), Beijing, China; ‡Department of Dermatology, The First Affiliated Hospital of Kunming Medical University, Kunming, China; §Department of Dermatology, Peking University First Hospital, Beijing, China; ‖Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China; ¶Department of Dermatology, Air Force General Hospital, PLA, Beijing, China; #Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China; **Peking University Clinical Research Institute, Beijing, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Feng
authors.forename: Qiuning
authors.initials: Q
authors.lastname: Sun
authors.forename: Li
authors.initials: L
authors.lastname: He
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.forename: Hongfu
authors.initials: H
authors.lastname: Xie
authors.forename: Guang
authors.initials: G
authors.lastname: Zhao
authors.forename: Jinhua
authors.initials: J
authors.lastname: Xu
authors.forename: Chen
authors.initials: C
authors.lastname: Yao
authors.forename: Hengjin
authors.initials: H
authors.lastname: Li
mesh_terms: D000328:Adult; D001763:Blepharoptosis / Q000139:chemically induced; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage* / Q000009:adverse effects; D004244:Dizziness / Q000139:chemically induced; D004311:Double-Blind Method; D005260:Female; D005546:Forehead; D006261:Headache / Q000139:chemically induced; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D009465:Neuromuscular Agents / Q000008:administration & dosage* / Q000009:adverse effects; D017060:Patient Satisfaction; D015595:Skin Aging / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: C000595968:Hengli BTX-A; D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A