Do children and adolescents with ADHD respond differently to atomoxetine?

Objective: Controversy exists over changes in tolerability and response to medications across the life span. Here the authors report data contrasting the efficacy and tolerability of atomoxetine between children and adolescents with attention-deficit/hyperactivity disorder (ADHD). Method: Data were analyzed for children ages 6-11 (510 atomoxetine, 341 placebo) and adolescents ages 12-17 (107 atomoxetine, 69 placebo) with DSM-IV-defined ADHD enrolled in similarly designed, double-blind, placebo-controlled trials. Efficacy measures included response rates, times to response, and mean changes from baseline to endpoint in the ADHD Rating Scale, Conners' Parent Rating Scale, and Clinical Global Impressions. Results: Adolescents had lower baseline ADHD scores compared with children. There were no statistically significant differences in the overall effects on ADHD symptoms, response rates, or time to response between age groups. Children, but not adolescents, had higher rates of somnolence and headache relative to placebo. No other clinically meaningful treatment differences were seen in adverse event rates, vital signs, weight, height, laboratory values, or ECG between children and adolescents. Conclusions: Acute atomoxetine treatment appears to be equally effective and tolerated in children and adolescents. These findings suggest that pharmacological differences in tolerability or ADHD symptom response are negligible between children and adolescents.