Switch to Lisdexamfetamine in the Treatment of Attention-Deficit Disorder at a Psychiatric Outpatient Clinic for School-Aged Children: A Danish Cohort Study

Objectives: This study aimed to examine switch from first-line methylphenidate (MPH) to lisdexamfetamine (LDX) in school-aged children with attention-deficit/hyperactivity disorder (ADHD). Methods: This is a retrospective observational study based on systematic review of patient records of all children (7-13 years) diagnosed with ADHD and referred to a Danish specialized outpatient clinic. The study included 394 children switching from MPH to LDX as either second-line or third-line treatment (atomoxetine ATX as second-line treatment) during the study period from April 1, 2013, to November 5, 2019. Results: One in five children switched from MPH to LDX at some point during the study period. The most frequent reasons for switching to LDX were adverse effects (AEs; 70.0% for MPH, 68.3% for ATX) and lack of efficiency (52.0% for MPH, 72.7% for ATX). Top five AEs of LDX were decreased appetite (62.4%), insomnia (28.7%), irritability/aggression (26.1%), weight decrease (21.1%), and mood swings (13.9%). MPH and LDX had similar AE profiles, yet most AEs were less frequent after switching to LDX. At the end of the study period, the majority were prescribed LDX as second-line rather than third-line treatment (86.1% in 2019). However, the likelihood of LDX as second-line treatment decreased with the number of psychiatric comorbidities, ADHD symptom severity as assessed by parents, and if AEs were a reason for MPH discontinuation. Among children observed for at least 1 year after initiation of LDX, 41.3% continued LDX treatment for a year or longer. LDX continuation was less likely if AEs were a reason for MPH discontinuation. Similarly to MPH and ATX, the most frequent reasons for LDX discontinuation were AEs (74.4%) and lack of efficiency (34.7%). Implications: The findings support LDX as an important option in the personalized treatment of children with ADHD and may support prescribers in the clinical decision-making on switching medication.