title: Pain associated with injection of botulinum A exotoxin reconstituted using isotonic sodium chloride with and without preservative: a double-blind, randomized controlled trial.
abstract: BACKGROUND
  Botulinum A exotoxin is used for various indications, including the treatment of dynamic forehead lines.
  
  
  OBJECTIVE
  To determine whether injection with botulinum A exotoxin reconstituted with preservative-containing normal saline (isotonic sodium chloride) is less painful than injection with exotoxin that has been reconstituted with preservative-free saline.
  
  
  METHODS
  Two arms: (1) retrospective study; (2) double-blind, randomized controlled trial.
  
  
  METHODS
  A multiple-physician dermatology practice.
  
  
  METHODS
  (1) Retrospective study-20 consecutive adult patients presenting for treatment of upper-face dynamic lines; (2) prospective study-15 consecutive adult patients presenting for treatment of upper-face dynamic lines.
  
  
  METHODS
  In prospective study only, one side (left or right) of the face was treated with exotoxin reconstituted with preservative-containing saline, and the other side, with exotoxin reconstituted with preservative-free saline.
  
  
  METHODS
  (1) Retrospective study-discomfort at current treatment (with preservative-containing saline) compared with discomfort with most recent prior treatment (with preservative-free saline); (2) prospective study-discomfort on the side treated with preservative-containing saline compared with discomfort on the side treated with preservative-free saline.
  
  
  RESULTS
  (1) Retrospective study-18 (90%) of 20 patients reported that treatment with exotoxin reconstituted with preserved saline was less painful than prior treatment with exotoxin reconstituted with preservative-free saline; (2) prospective study-15 (100%) of 15 patients reported less pain in the side of their face treated with exotoxin reconstituted with preservative-containing saline (P<.001). Pain on the preservative-containing side was 54% less. No difference in treatment efficacy between the sides was observed by investigators or patients.
  
  
  CONCLUSIONS
  Use of preservative-containing saline to reconstitute botulinum A exotoxin can significantly decrease patient discomfort on injection.
authors.affiliation: SkinCare Physicians, Chestnut Hill, Massachusetts, USA. murad@alam.com
authors.forename: Murad
authors.initials: M
authors.lastname: Alam
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Dover
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Arndt
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007267:Injections; D007552:Isotonic Solutions; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000008:administration & dosage*; D010146:Pain / Q000209:etiology*; D011310:Preservatives, Pharmaceutical; D011446:Prospective Studies; D012189:Retrospective Studies; D012965:Sodium Chloride
chemical_list: D007552:Isotonic Solutions; D009465:Neuromuscular Agents; D011310:Preservatives, Pharmaceutical; D012965:Sodium Chloride; D019274:Botulinum Toxins, Type A