title: [Botulinum toxin A in chronic refractory migraine: premarketing experience].
abstract: BACKGROUND
  Chronic migraine is very disabling, with medication overuse commonly associated. The recent approval of botulinum toxin-A -OnabotulinumtoxinA (OnabotA)- means a hallmark.
  
  
  OBJECTIVE
  To describe our experience in compassionate use before approval.
  
  
  METHODS
  35 cases with chronic migraine assessed between July 2009-December 2011 in a specialized headache consultation. 100 U of OnabotA were injected in 21 points over the facial and pericranial muscles, according to a modified PREEMPT protocol. We determined before and after treatment: number of episodes and migraine days; pain intensity and days of disability extracted from MIDAS score, and data regarding drug intake. After follow-up, new injections were given at intervals dictated by individualized response timing. Therapeutic response was considered when: intensity of pain was reduced to a half o ≥ 4 VAS points, or the number of monthly days of pain descended ≥ 7/month, or the case converted to non-drug overuser.
  
  
  RESULTS
  In 27 cases (80%) it was proved clinical improvement. This effect was confirmed by: a reduction in headache severity, reflected as much in pain intensity (VAS scale < 0.001) as in the number of days with disability (3.2 vs 0.4, p < 0.001); an improvement in the number of monthly days of pain (19.8 vs 13.8, p < 0.05; a significant decrease in the number of cases of medication overuse (69% vs 13%, p < 0.01). Mean duration of effect was 15 weeks and mean follow-up 9.8 months.
  
  
  CONCLUSIONS
  OnabotA disclosed efficacy as prophylactic treatment of chronic migraine. It is mainly expressed as a reduction of pain intensity. Medication overuse also descended. Adverse events were sparse.
authors.affiliation: Departamento de Neurociencias, Universidad del Pais Vasco UPV/EHU, Bilbao, España. luiscarlosalvaro@yahoo.es
authors.forename: Luis C
authors.initials: LC
authors.lastname: Álvaro-González
authors.forename: José M
authors.initials: JM
authors.lastname: Fernández-García
authors.forename: Inés
authors.initials: I
authors.lastname: Aranzábal-Alustiza
authors.forename: Beatriz
authors.initials: B
authors.lastname: Castillo-Calvo
authors.forename: Imanol
authors.initials: I
authors.lastname: Iriondo-Etxenagusia
authors.forename: Alfredo
authors.initials: A
authors.lastname: Rodríguez-Antigüedad
mesh_terms: D000041:Absenteeism; D000328:Adult; D000368:Aged; D000700:Analgesics / Q000009:adverse effects / Q000627:therapeutic use; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000627:therapeutic use*; D057176:Compassionate Use Trials; D004351:Drug Resistance; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D020773:Headache Disorders / Q000188:drug therapy / Q000517:prevention & control*; D051271:Headache Disorders, Secondary / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000188:drug therapy / Q000517:prevention & control*; D010147:Pain Measurement; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014363:Tryptamines / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000700:Analgesics; D014363:Tryptamines; D019274:Botulinum Toxins, Type A