(FDA approved in bold)

• Migraine prophylaxis (children and adults)
  
• Cluster headache prophylaxis
  
• Treatment of serotonin syndrome
  
• Anxiety/social phobia

• An antihistamine and 5-HT2 receptor antagonist that is structurally related to tricyclic antidepressants. Has weak anticholinergic effects and may act as a calcium channel blocker at high doses. The relative importance of each action in headache prophylaxis is unclear. Prevention of cortical spreading depression may be the mechanism of action for all migraine preventatives

• Migraines may decrease in as little as 2 weeks, but can take up to 2 months to see full effect

• Migraine – goal is a 50% or greater decrease in migraine frequency or severity. Consider tapering or stopping if headaches remit for more than 6 months or if considering pregnancy

• Increase to highest tolerated dose
  
• Migraine: address other issues, such as medication-overuse, other coexisting medical disorders, such as anxiety, and consider changing to another agent or adding a second agent

• Migraine: For some patients with migraine, low-dose polytherapy with 2 or more drugs may be better tolerated and more effective than high-dose monotherapy. May use in combination with AEDs, antidepressants, natural products, and non-medication treatments, such as biofeedback, to improve headache control

• Monitor weight during treatment