Botulinum toxin A (onabotulinumtoxinA; BOTOX®) may be beneficial in patients with intractable, chronic migraine that has failed to respond to at least three conventional preventive medications.
The injections are administered to the scalp and temple. They may reduce the frequency and severity of migraine attacks after 2-3 months of injections.
The injections are expensive and must be administered every 2-3 months to maintain their effectiveness.
The most appropriate duration of prophylactic therapy has not been determined. In most patients who are receiving prophylaxis, therapy must be continued for at least 3-6 months.
Cyproheptadine and gabapentin have unproven efficacy in migraine prevention. Common first-line preventive medicines with high efficacy include beta-blockers, tricyclic antidepressants, divalproex, and topiramate.
