Effects of atomoxetine on growth in children with attention-deficit/hyperactivity disorder following up to five years of treatment.

Objective: To examine the effects on growth of long-term pharmacological treatment for attention-deficit/hyperactivity disorder (ADHD), we present findings from an ongoing 5-year study of the efficacy and safety of treatment with atomoxetine.

Methods: North American patients, 6-17 years old at study entry (N = 1,312) and with Diagnostic and Statistical Manual of Mental Disorders,4th edition (DSM-IV) ADHD, were studied under open-label atomoxetine treatment. Sixty-one were studied up to 5 years.

Results: After 1 month's treatment, patients weighed less than expected from their starting percentiles relative to population norms, with a maximum shortfall at 15 months and a return to expected weight by 36 months. Patients were slightly shorter than expected after 12 months, reaching a maximum shortfall at 18 months and returning to expected height by 24 months. Patients in the top quartile for body mass index (BMI) or weight at baseline, and those in the third quartile for height, showed 5-year decreases from expected values. Those below median height at baseline showed increases relative to expected values.

Conclusions: These interim results indicate that continuous atomoxetine treatment for up to 5 years has little or no long-term effect on juvenile growth and final stature for most patients, although persistent decreases from expected may occur in some patients who are larger than average before treatment.