Attention-deficit/hyperactivity disorder: medication treatment-dosing and duration of action

Several trends have affected the current standards for medication dosing recommendations for the treatment of attention-deficit/hyperactivity disorder (ADHD). Empirical evidence that treatment can effect improvement across multiple domains of impairment has encouraged optimizing treatment throughout the day. For stimulants, the value of increasing the dose to improve effect has replaced former notions of minimizing exposure to medication by treating at the lowest dose demonstrating effect. Several new stimulant formulations control the rate of dose delivery to optimize effect for longer intervals than immediate-release medication. This avoids morbidity associated with improper dose sculpting, inherent ups and downs of effect, and poorer adherence to multiple daily doses of shorter-acting products. Dosing of the new nonstimulant agent atomoxetine (Strattera) is based primarily on weight. Atomoxetine appears to have a longer duration of action in children and adolescents, but in adults it requires twice-daily dosing to maintain effect across the day. Whereas its overall effect size is smaller than stimulant agents, there is no way to predict an individual's response in advance, and for some atomoxetine may be the optimal medication treatment. Some head-to-head comparison studies between long-acting stimulant preparations and atomoxetine, especially those focused on duration of effective action, are likely.