Efficacy and safety of atomoxetine hydrochloride in Korean adults with attention-deficit hyperactivity disorder

Introduction: This article aims to assess the efficacy and safety of atomoxetine in Korean adults with attention-deficit hyperactivity disorder (ADHD). Methods: This post hoc double-blind, placebo-controlled study of atomoxetine (40-120mg/day) over 10 weeks in adults with ADHD at 45 Japanese, Korean, and Taiwanese study sites focused on patient data from Korea (atomoxetine, n=37; placebo, n=37). Primary efficacy outcome was change in baseline-to-endpoint Conners' Adult ADHD Rating Scale-Investigator-rated: Screening Version (CAARS-Inv:SV) Total ADHD Symptoms score. Secondary efficacy outcomes included changes in Adult ADHD Quality of Life (AAQoL) total, Behavior Rating Inventory of Executive Function-Adult Version Self-Report (BRIEF-A:Self-Report), and Clinical Global Impression-ADHD-Severity (CGI-ADHD-S) scale scores. Results: Atomoxetine-treated patients demonstrated a mean 18.9-point reduction in CAARS-Inv:SV total ADHD Symptoms score, compared with the 7.45-point reduction in placebo-treated patients (P≤0.01). Significantly greater improvement was found for atomoxetine versus placebo in CGI-ADHD-S (P≤0.01), BRIEF-A:Self-Report global executive composite (P≤0.05), and metacognition index (P≤0.01) executive function scores. Nausea, decreased appetite, and dry mouth were reported with significantly greater frequency by atomoxetine-treated patients, and only one placebo-treated patient discontinued because of adverse event. A 2.1-kg reduction in weight and a 7.5-beat/minute increase in pulse rate were observed in atomoxetine-treated patients. Discussion: These data support a significant benefit of 80- to 120-mg once daily atomoxetine versus placebo for treatment of ADHD in adult Korean patients. A high placebo response rate was observed in this adult Korean sample; a higher discontinuation rate was also observed in atomoxetine-treated patients. These observations warrant further investigation.