A randomized, double-blind, placebo-controlled study of atomoxetine in Japanese children and adolescents with attention-deficit/hyperactivity disorder

Abstract

Objectives: Until the recent approval of methylphenidate (MPH), Japan had no approved treatment for attention-deficit/hyperactivity disorder (ADHD). The need still exists for an effective, safe, nonstimulant treatment. This first placebo-controlled Japan study of an ADHD nonstimulant therapy assessed atomoxetine efficacy and safety to determine the optimal dose for controlling ADHD symptoms in children and adolescents.

Methods: A total of 245 Japanese children and adolescents, aged 6-17 years and diagnosed with ADHD, were randomly assigned to receive placebo or one of three atomoxetine doses (0.5, 1.2, and 1.8 mg/kg per day) over 8 weeks. Symptoms were assessed with the Japanese Attention-Deficit/Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator scored and integrated with teacher reports (ADHD RS-IV-J:I/Sch). Adverse events, vital signs, laboratory tests, and electrocardiograms (ECGs) were obtained for safety analysis.

Results: In all, 234 patients completed the study. Atomoxetine at 1.8 mg/kg per day was significantly superior to placebo in reducing ADHD symptoms (p = 0.01; one-sided). Decreased appetite and vomiting were significantly greater in the atomoxetine treatment groups; however, no clinically significant differences were observed. Two patients discontinued due to affect lability and headache. A linear dose-response and vital signs similar to those from other atomoxetine studies were observed.

Conclusion: Atomoxetine provides an effective and safe nonstimulant option for the treatment of Japanese pediatric patients with ADHD.