Growth and Puberty in a 2-Year Open-Label Study of Lisdexamfetamine Dimesylate in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

Background: Stimulant medications for the treatment of attention-deficit/hyperactivity disorder have a history of safe and effective use; however, concerns exist that they may adversely affect growth trajectories in children and adolescents. Objective: The objective of this study was to evaluate the longer-term effects of lisdexamfetamine dimesylate on weight, height, body mass index and pubertal development in children and adolescents with attention-deficit/hyperactivity disorder. Methods: Children and adolescents aged 6–17 years with attention-deficit/hyperactivity disorder took open-label lisdexamfetamine dimesylate (30, 50 or 70 mg/day) in this open-label 2-year safety and efficacy study. Safety evaluations included treatment-emergent adverse events, measurement of weight, height and body mass index, and self-reported pubertal status using Tanner staging. Results: The safety analysis population comprised all enrolled participants (N = 314) and 191 (60.8%) completed the study. Weight decrease was reported as a treatment-emergent adverse event in 63 participants (20.1%) and two participants (0.6%) discontinued the study as a result of treatment-emergent adverse events of weight decrease. Growth retardation of moderate intensity was reported as a treatment-emergent adverse event for two participants. From baseline to the last on-treatment assessment, there were increases in mean weight of 2.1 kg (standard deviation 5.83) and height of 6.1 cm (standard deviation 4.90), and a body mass index decrease of 0.5 kg/m2(standard deviation 1.72). Mean weight, height and body mass index z-scores decreased over the first 36 weeks of the study and then stabilised. Changes from baseline to the last on-treatment assessment in mean z-scores for weight, height and body mass index were significantly less than zero (− 0.51, − 0.24 and − 0.59, respectively; nominal p < 0.0001). The proportion of participants with a z-score of < − 1 ranged from 5.1% (baseline) to 22.1% (week 84) for weight, 8.2% (baseline) to 12.6% (week 96) for height, and 8.3% (baseline) to 28.8% (week 96) for body mass index. Thirteen participants (4.1%) shifted to a weight below the fifth percentile at the last on-treatment assessment from a higher weight category at baseline. At the last on-treatment assessment, most participants remained at their baseline Tanner stage or had shifted higher. Conclusions: Findings from this comprehensive examination of growth outcomes associated with lisdexamfetamine dimesylate treatment over 2 years were consistent with previous studies of stimulant medications. Whilst mean weight and height increased over the course of the study, there was a small but transient reduction in mean weight, height and body mass index z-scores. A small increase in the proportion of participants in the lowest weight and body mass index categories highlights the importance of the regular monitoring of weight and height. There was no evidence of delayed onset of puberty. ClinicalTrials.gov identifier: NCT01328756.