title: Botulinum toxin type A in the treatment of bilateral primary axillary hyperhidrosis: efficacy and duration with repeated treatments.
abstract: BACKGROUND
  Botulinum toxin type A (BTX-A) has been shown to be effective for the temporary reduction of local hyperhidrosis.
  
  
  OBJECTIVE
  To investigate the duration of efficacy of BTX-A with repeat treatments for axillary hyperhidrosis.
  
  
  METHODS
  Patients who completed a prior randomized, controlled, parallel-group study comparing BTX-A with vehicle for bilateral primary axillary hyperhidrosis were eligible for this 18-month, open-label, noncomparative, follow-up study. Patients had to request further treatment, fulfill the preceding study inclusion/exclusion criteria, and have spontaneous sweat production that was more than 50% of the baseline value of the previous study. Patients received up to four treatments of intradermal BTX-A (2 mL, 50 U). All of the 12 patients who were enrolled completed the study. Two of the 12 patients (17%) were previously treated with placebo.
  
  
  RESULTS
  In the 18 months of study and follow-up, five patients (42%) required a total of two active injections. Three patients (25%) required a total of three active injections, and four patients (33%) required a total of four active injections. The response rate was 83% (10 of 12) at 4 weeks after the first treatment. The mean percentage change from baseline in overall sweat production was approximately 80% at Week 4. The mean time between the first and second treatment in this study was just over 29 weeks, with a range of 17.8 to 57.5 weeks.
  
  
  CONCLUSIONS
  BTX-A is an effective repeat treatment for axillary hyperhidrosis giving variable but clinically helpful remission. No clinically relevant changes in vital signs or safety parameters were noted.
authors.affiliation: Cranley Clinic, London, United Kingdom.
authors.forename: Phillipa L
authors.initials: PL
authors.lastname: Lowe
authors.forename: Suzanne
authors.initials: S
authors.lastname: Cerdan-Sanz
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Lowe
mesh_terms: D000328:Adult; D001365:Axilla; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006945:Hyperhidrosis / Q000188:drug therapy*; D008297:Male; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A