Two years of methylphenidate use did not affect height and weight velocity.

Methylphenidate, a central nervous system stimulant, is approved by the US Food and Drug Administration as first-line pharmacotherapy for attention deficit/hyperactivity disorder (ADHD) in children aged 6 years and older. Although short-term safety and efficacy of methylphenidate for ADHD is well established, concerns exist about longer-term safety and effect on paediatric growth.

European researchers prospectively followed 756 treatment-naive children (mean age, 9 years; age range, 6 to 17 years) with ADHD who were beginning treatment with methylphenidate. Control cohorts were 391 nonmedicated children with ADHD and 263 children without ADHD. Propensity score analysis was used to control for baseline differences between groups.

At two years, no significant differences were observed among cohorts in height and weight velocity, neurological outcomes or psychiatric outcomes. Patients in the methylphenidate group had small but statistically significant increases in mean blood pressure (from 108/65 to 113/67 mmHg) and mean resting heart rate (from 80 to 83 beats/minute). Most participants were still prepubertal at study end, so researchers were unable to assess the effect of methylphenidate on pubertal growth and development. Almost half of study participants (47%) dropped out of the study before two-year follow up was complete.

Comment: Primary care clinicians are well positioned to manage pharmacotherapy for patients with ADHD. Although no adverse longer-term effects on growth were observed during two years of methylphenidate use, most children will take these medications for considerably longer. Frequency of follow up for children on stimulant medications should be individualised, but assessing height, weight, blood pressure and heart rate at least annually is reasonable.

Marie Claire O’Dwyer, MB BCh BAO, MPH, Clinical Assistant Professor in Family Medicine, University of Michigan Medical School, Ann Arbor, USA.

Man KKC, et al. Long-term safety of methylphenidate in children and adolescents with ADHD: 2-year outcomes of the Attention Deficit Hyperactivity Disorder Drugs Use Chronic Effects (ADDUCE) study. Lancet Psychiatry 2023; 10: 323-333.

This summary is taken from the following Journal Watch titles: General Medicine, Ambulatory Medicine, Pediatrics and Adolescent Medicine, Psychiatry.