title: Dosage changes in patients with long-term botulinum toxin use for laryngeal dystonia.
abstract: OBJECTIVE
  To investigate the dosage consistency of botulinum toxin injections in patients with long-term treatment for laryngeal dystonia.
  
  
  METHODS
  Chart review.
  
  
  METHODS
  Patients with laryngeal dystonia who had received at least 20 injections to the thyroarytenoid muscle were selected. Change of botulinum toxin dose, patient-reported effective weeks, and intervals between injections were investigated; data from the first five injections were excluded to eliminate initial dose titration.
  
  
  RESULTS
  Fifty-five patients with an average follow-up of 12.5 years were identified. Mean dose of botulinum toxin was 2.37 +/- 1.6 U at the sixth injection; there was a decrease in mean dose over time, which became statistically significant at the 13th injection with a mean dose of 2.02 +/- 1.16 U. Mean duration of good effect and treatment intervals showed no significant change over time.
  
  
  CONCLUSIONS
  Botulinum toxin dose needed for a constant response in treatment of laryngeal dystonia decreases over time, without any accompanying change in effective weeks and intervals.
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Gulhane Military Medical Academy, Ankara, Turkey. hbirkent@yahoo.com
authors.forename: Hakan
authors.initials: H
authors.lastname: Birkent
authors.forename: Nicole
authors.initials: N
authors.lastname: Maronian
authors.forename: Patricia
authors.initials: P
authors.lastname: Waugh
authors.forename: Albert L
authors.initials: AL
authors.lastname: Merati
authors.forename: David
authors.initials: D
authors.lastname: Perkel
authors.forename: Allen D
authors.initials: AD
authors.lastname: Hillel
mesh_terms: D001905:Botulinum Toxins / Q000008:administration & dosage*; D004421:Dystonia / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D007818:Laryngeal Diseases / Q000188:drug therapy*; D007821:Laryngeal Muscles; D008297:Male; D008875:Middle Aged
chemical_list: D001905:Botulinum Toxins