More than 6 million children and adolescents in the United States have migraines.1-3 The majority continue to have headaches into adulthood, taking a toll on the U.S. economy of approximately $36 billion and resulting in substantial effects on quality of life.4-7 Pediatric clinical practice guidelines for migraine treatment are consensus based rather than evidence based,8,9 with no Food and Drug Administration (FDA)–approved migraine prevention medication for children younger than 12 years of age.

The Childhood and Adolescent Migraine Prevention (CHAMP) trial tested the effects of amitriptyline and topiramate in comparison with each other and with placebo in pediatric migraine. Previous studies of this disorder have shown high placebo response rates (up to 50 to 60%).10-14 The two medications were chosen on the basis of a survey of pediatric headache specialists, who indicated that these drugs were the most commonly used preventive medications.8,9 Both the International Headache Society Clinical Trial Guidelines15 and respondents to the same survey indicated that a clinically meaningful end point is a reduction of 50% or more in days on which a patient had headache. The CHAMP trial involved three hypotheses related to the primary end point of a relative reduction of 50% or more in the number of headache days from the 28-day baseline period to the final 28 days of the 24-week trial: that amitriptyline would provide greater relief than placebo, that topiramate would provide greater relief than placebo, and that one of the active treatments would provide greater relief than the other active treatment.