Long-term effects of extended-release mixed amphetamine salts treatment of attention- deficit/hyperactivity disorder on growth

OBJECTIVE: The aim of this study was to examine the long-term effects of extended-release mixed amphetamine salts (MAS-XR) with 10-30-mg doses on the growth of children being treated for attention-deficit/hyperactivity disorder (ADHD). METHODS: Long-term growth data were collected from 568 children, 6-12 years of age, enrolled in a multicenter, open-label study of the safety of MAS-XR for the treatment of ADHD symptoms over the course of 6-30 months. RESULTS: Children taking MAS-XR grew less than expected, based on the norms provided by the Centers for Disease Control (CDC). The losses in expected weight and body mass index (BMI) were greatest for the heaviest children, and the losses in expected height were greatest for the tallest children. For weight, height, and BMI, we found that nearly all of the growth deficits occurred in year one. For each of these growth parameters, the loss in expected growth was not significant in the second year of treatment. CONCLUSIONS: Our results suggest that treatment with MAS-XR can lead to reductions in expected height and weight that are not fully rectified over the course of treatment, although they did show attenuation with treatment over time. Although this does not eliminate the need for clinicians to monitor growth, as they should for all stimulant formulations, it suggests that deficits in growth are not likely to be a clinical concern for most children treated with MAS-XR.