title: OnabotulinumtoxinA (botulinum toxin type-A) in the prevention of migraine.
abstract: BACKGROUND
  Migraine is a highly prevalent disorder with the potential to progress into a chronic disease. The disability and health effects associated with frequent episodes of migraine underscore the value of preventive pharmacotherapy.
  
  
  METHODS
  OnabotulinumtoxinA has been studied as a migraine preventive in numerous clinical trials and in a variety of subpopulations with migraine. Overall, results from the clinical trials are mixed. However, the largest and most recent parallel studies (n = 1330) conducted on subjects with chronic migraine achieved statistically significant efficacy on numerous endpoints including the primary endpoint of reduction of headache days.
  
  
  RESULTS
  This article reviews several clinical studies using onabotulinumtoxinA in migraine prevention and highlights some of the inherent difficulties defining study endpoints and outcomes that are relevant to clinician, patients, and regulatory agencies.
  
  
  CONCLUSIONS
  Clinical trials utilizing onabotulinumtoxinA as a preventive therapy for migraine has revealed mixed results. In part this reflects the inherent difficulties in study design such as defining different subpopulations of migraine sufferers and trial end points that are meaningful to patient populations. Recent studies of subjects with chronic migraine appear to have positive results. If confirmed this would be the first preventive medication indicated specifically for chronic migraine.
authors.affiliation: Headache Care Center, 3805 S. Kansas Expressway, Springfield, MO 65807, USA. rcady@banyangroupinc.com
authors.forename: Roger K
authors.initials: RK
authors.lastname: Cady
mesh_terms: D000818:Animals; D019274:Botulinum Toxins, Type A / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D017326:Clinical Trials, Phase III as Topic; D006801:Humans; D008881:Migraine Disorders / Q000517:prevention & control*; D009465:Neuromuscular Agents / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A