Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder that affects children and adolescents. The use of medication, such as lisdexamfetamine dimesylate (LDX; Vyvanse) and delayed release/extended-release methylphenidate (DR/ER-MPH; Jornay PM), is common in managing symptoms of ADHD. However, there is limited research on the impact of these medications on growth trajectories in youth. In this article, we will analyze recent findings on the growth effects of LDX and DR/ER-MPH in comparison to osmotic release oral system methylphenidate (OROS MPH; Concerta) in youth with ADHD.
According to a study by Weddige et al., youth who were prescribed DR/ER-MPH experienced a greater weight trajectory in the first year after starting treatment compared to those on LDX. The estimated post-index slope for weight was significantly higher in the DR/ER-MPH group (7.22) compared to the LDX group (2.65). The model-adjusted average weight for youth on LDX after one year was approximately 43 kg, while it was around 47 kg for those on DR/ER-MPH. These findings suggest that DR/ER-MPH may lead to greater weight gain in youth with ADHD.
Although there were no significant differences in height trajectories between the two medication groups, youth on DR/ER-MPH showed numerically higher average heights 1 year after starting treatment compared to those on LDX. The estimated post-index slope for height was 5.72 for DR/ER-MPH and 4.00 for LDX. At the 1-year mark, average heights were approximately 146 cm for youth on LDX and 148 cm for those on DR/ER-MPH. These findings suggest that DR/ER-MPH may have a slight advantage in promoting height growth in youth with ADHD.
Weddige’s group also compared the growth trajectories of youth on DR/ER-MPH with those prescribed OROS MPH. Although there were no statistically significant differences, youth on DR/ER-MPH showed numerically higher height and weight trajectories within the first year of starting medication. These findings suggest that DR/ER-MPH may have comparable growth effects to OROS MPH in youth with ADHD.
DR/ER-MPH has unique pharmacokinetics compared to other ADHD medications. It is an evening dosed, delayed-release, and extended-release methylphenidate that is absorbed in the colon. The absence of an immediate-release component and a gradual colonic absorption result in a monophasic pharmacokinetic profile with smoother plasma concentration. This smooth profile is hypothesized to be associated with less appetite suppression throughout the day, which may explain the greater weight trajectory observed in youth on DR/ER-MPH.
There are several limitations to consider in this study. The small sample size of patients on DR/ER-MPH may have contributed to greater variability in their growth trajectory models. Additionally, the study period coincided with the onset of the COVID-19 pandemic, which may have influenced normal growth patterns in youth. Further research with larger sample sizes and longer study durations is necessary to confirm these findings.
The findings from this study suggest that youth with ADHD experience mildly different growth trajectories depending on the medication they are prescribed. DR/ER-MPH appears to be associated with greater weight gain and potentially higher height growth compared to LDX. However, further research is needed to fully understand the long-term effects of these medications on growth in youth with ADHD. Healthcare providers should carefully consider the potential impact on growth when selecting ADHD medications for their patients.