Effectiveness of amitriptyline in the prophylactic management of childhood headaches.

OBJECTIVE: To study the effectiveness of a standardized dose of amitriptyline, 1 mg/kg, for childhood headaches.
BACKGROUND: Amitriptyline has been shown to be effective for the prophylaxis of migraine in adults. Studies in children, however, have been quite limited. In adults, the suggested effective dose range is 10 to 150 mg. In children, a standardized dosage is often not used, resulting in a dosage range in clinical practice that often varies from a very low dose to a dose equivalent to that used in adults.
METHODS: Children with more than three headaches per month were treated with amitriptyline, slowly increasing the dose to 1 mg/kg per day. The frequency, severity, and duration of their headaches were initially evaluated and subsequently measured at each follow-up evaluation. Two hundred seventy-nine children had headaches occurring frequently enough to indicate prophylactic treatment. Of these children, 192 (68.8%) were treated with amitriptyline. The average age at presentation was 12.0 (+/- 3.0) years. The ratio of boys to girls was 1:1.74. The average frequency of headaches was 17.1 (+/- 10.1) days per month. The average severity was 6.84 (+/- 1.67) on a 10-point pain scale. The average duration was 11.5 (+/- 15.0) hours. The most frequent diagnoses using International Headache Society criteria were migraine (60.6%), migraine with aura (7.9%), and tension-type headache (10.4%). Of these children, 146 have been seen for at least one follow-up examination, occurring on average 67.3 (+/- 32.3) days after beginning prophylactic treatment.
RESULTS: A total of 84.2% of the children reported an overall perception of being better, while 11.6% reported being the same. The frequency of headaches improved to 9.2 (+/- 10.0) days per month. The average severity was reduced to 5.1 (+/- 2.1), and the average duration was reduced to 6.3 (+/- 11.1) hours. If daily or continuous headaches were excluded, the improvements were more marked. Minimal side effects were reported from these children and their families. Long-term evaluation (156 to 415 days) showed continued sustained improvement.
CONCLUSIONS: Amitriptyline is an effective prophylactic medication for children with frequent headaches. A standardized dosing regimen results in a significant number of children responding with minimal side effects. The children are able to tolerate this dosing scheme and demonstrate good adherence to a dosing schedule of once a day.