(FDA approved in bold)

• Hypersensitivity reactions
  
• Migraine prophylaxis (children and adults)
  
• Tension-type headache prophylaxis
  
• Nightmares/post-traumatic stress disorder

• Antihistamine and anticholinergic activity. 5-HT2_A/C receptor antagonist and perhaps a calcium-channel blocker. 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 preventive drugs

• 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