Open-label amantadine in children with attention-deficit/hyperactivity disorder

Objectives: The purpose of this study was to explore the possible efficacy and tolerability of amantadine in the treatment of attention-deficit/ hyperactivity disorder (ADHD) in stimulantnaïve children. Methods: Twenty four children (5-13 years old) with Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) ADHD (4 inattentive, 2 hyperactive, and 18 combined type) entered a 6-week open-label treatment with amantadine (50-150 mg) given as a single morning dose. Parent and teacher ADHD rating scales and the parent Child Behavior Checklist (CBCL) were administered at baseline and at week 6. Results: Twenty three subjects completed the 6-week treatment. One child dropped out at week 2 because of persistent headache, and another 12 children reported adverse effects, most commonly transient appetite decrease. The parent ADHD score decreased from mean 41.04 ± D 6.9 at baseline to 28.9 ± 8.7 at week 6 (p < 0.001, effect size d = 1.5), and the teacher ADHD score from 35.8 ± 9.6 to 26.2 ± 9.5 (p < 0.001, effect size d = 1.0). Response rate (a 25% or greater decline in ADHD score) was 58% based on parents and 46% based on teachers. Conclusions: These data suggest that amantadine has acceptable acute tolerability at single doses up to 150 mg/day and is possibly efficacious in decreasing ADHD symptoms, although its activity appears to be more modest than that of stimulant medications.