Cochrane Review: What is the Evidence for the Prevention of Migraines Using Botulinum toxins?

BACKGROUND AND PURPOSE:

• FDA has approved onabotulinumtoxinA as a preventative treatment for adults with chronic migraine who have 15 or more days each month with headache lasting 4 or more hours each day in people ≥18 years of age
• Mechanism not well understood
  • May inhibit release of neuropeptides that are involved in the initiation of the migraine
• Herd et al. (Cochrane Library, 2018) examined how Botulinum toxin type A compares to active treatment for adults with chronic or episodic migraines

METHODS:

• Systematic review and meta-analysis
• Literature search of RCTs of botulinum toxin injections into the head and neck for prophylaxis of chronic or episodic migraine in adults
• Studies were selected that compared as follows
  • Botulinum toxin vs. placebo
  • Botulinum toxin vs. other active treatment
• Too avoid bias, two independent researchers selected trials and extracted data
• GRADE methods used to assess result quality

RESULTS:

• 90 articles describing 28 trials and 4,190 participants were included in the study
• Botulinum toxin vs placebo
  • Botulinum toxin reduced the number of chronic migraine days per month by by 1.9 days (95% CI, -2.7 to -1.0, 2 trials, high-quality evidence)
  • Severity of migraines with botulinum was also reduced but larger trials required
  • Botulinum toxin groups had a greater risk for adverse events
    • Risk ratio (RR) 1.28, (95% CI 1.12 to 1.47; moderate-quality evidence)
  • Botulinum toxin vs other prophylactic agents
    • Individual trials reported no differences between groups for multiple efficacy measures
    • No difference was seen when comparing side effects to other oral treatments
    • Patients taking botulinum toxin were 4x less likely to stop their treatment due to adverse events compared to an alternative (P = 0.02, 2 trials, N = 119)
  • Botulinum toxin side effects were reported in approximately 60%, consisted mostly of droopy eyelid or muscle weakness (40% reported in placebo groups)

CONCLUSION:

• The quality of the evidence is limited
• Botulinum toxin type A may reduce number of migraines in chronic migraine sufferers by 2 days a month

Learn More – Primary Sources:

Botulinum toxins for the prevention of migraine in adults