Atomoxetine

Abstract

Atomoxetine, formerly tomoxetine, is a selective norepinephrine reuptake inhibitor and a new, nonstimulant treatment for attention deficit hyperactivity disorder (ADHD). In vitro, ex vivo and in vivo studies have shown that atomoxetine is a highly selective antagonist of the presynaptic norepinephrine transporter with little or no affinity for other noradrenergic receptors or other neurotransmitter transporters or receptors. In four randomized, placebo-controlled clinical trials conducted over 6-9 weeks in children and adolescents with ADHD, atomoxetine (total daily dose 1-1.8 mg/kg administered in one or two doses daily) reduced symptoms (hyperactivity, impulsiveness and inattention) as determined by the reduction in ADHD total score (34-38% with atomoxetine versus 13-15.7% with placebo [p < 0.05]). Atomoxetine also significantly improved ADHD subscale rating scores (p < 0.05 and p < 0.001), psychosocial well-being (p < 0.05) and ADHD-related problem behavior according to parent and teacher ratings (p < 0.05). Atomoxetine was well tolerated in clinical trials and discontinuation rates due to adverse events were low (<5%). The most common treatment-related adverse event was decreased appetite. Atomoxetine shows no abuse potential and is not a controlled substance in the US.