Long-term safety and tolerability of atomoxetine in Japanese adults with attention deficit hyperactivity disorder.

INTRODUCTION: The primary aim of this study was to evaluate the long-term safety/tolerability of atomoxetine in Japanese adults with attention deficit hyperactivity disorder (ADHD). METHODS: This 48-week, open-label extension study involved participants with ADHD who completed a 10-week randomized controlled trial of atomoxetine. Participants received atomoxetine 40 mg/day, followed by step-wise titration to a maximum of 120 mg/day. The primary outcome was safety/tolerability. Secondary outcomes were symptoms of ADHD (Conners' Adult ADHD Rating Scales-Investigator Rated: Screening Version 18-item total score), quality of life (Adult Attention-Deficit/Hyperactivity Disorder Quality of Life scale), and executive function (Behavior Rating Inventory of Executive Function-Adult Version: Self-report). RESULTS: Of the 39.5% of participants overall who discontinued the study, 15.9% (37/233) of participants discontinued because of adverse events (AEs), primarily nausea (4.3%; 10/233). Overall, 93.6% (218/233) of participants experienced treatment-emergent AEs (TEAEs), most commonly nausea (56.2%; 131/233), nasopharyngitis (25.3%; 59/233), thirst (19.3%; 45/233), headache (17.2%; 40/233), and decreased appetite (16.3%; 38/233). Most TEAEs (70.8%; 165/233) were mild in intensity. Overall, 79.8% (186/233) of participants experienced ≥1 adverse drug reaction, primarily nausea (55.4%; 129/233). Five participants experienced serious AEs during the open-label extension; none was related/possibly related to treatment. There were statistically significant increases in vital signs and decreases in body weight that were not considered clinically significant. Symptoms of ADHD, quality of life, and executive function were significantly improved from baseline to endpoint (P < 0.05). DISCUSSION: Despite discontinuations due to the long-term, open-label design, AE related discontinuations were modest, suggesting that atomoxetine has acceptable long-term safety and tolerability in Japanese adults with ADHD. Symptoms of ADHD improved and remained improved throughout the study.