The objective of this study was to evaluate the safety and efficacy of dexmethylphenidate extended-release (d-MPH-ER) 30 versus 20 mg in children with attention-deficit/hyperactivity disorder (ADHD) in a 12-hour laboratory classroom setting. In a randomized, double-blind, 3-period × 3-treatment, crossover study, children aged 6 to 12 years with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-diagnosed ADHD previously stabilized on MPH (40-60 mg/d) or D-MPH (20-30 mg/day) [corrected] were randomized to receive D-MPH-ER 20 mg/day, 30 mg/day, [corrected] or placebo for 7 days each. Primary efficacy measurements were change in the average SKAMP-Combined [corrected] score from predose to 10, 11, and 12 hours postdose [Avg(10-12)] between 30 mg [corrected] and 20 mg D-MPH-ER. Safety was assessed by adverse events, (AEs), [corrected] vital sign monitoring, and ECGs. [corrected] A total of 165 children were randomized, and 162 included in the intent-to-treat analysis. Mean Avg (10-12) change from pre-dose [corrected] in SKAMP-Combined score was significantly greater for D-MPH-ER 30 mg (-4.47) compared with D-MPH-ER 20 mg (-2.02; P = 0.002). Most common adverse events (≥ 3% in any group) were decreased appetite (6.1%, 4.9%, and 0%), headache (4.3%, 4.3%, and 1.9%), abdominal pain (3.7%, 3.1%, and 3.1%), and tachycardia (1.2%, 3.1%, and 0.6%) for D-MPH-ER 30 mg, D-MPH-ER 20 mg, and placebo, respectively). Significantly greater improvement in ADHD symptoms was noted with D-MPH-ER 30 mg compared with D-MPH-ER 20 mg at hours 10 through 12. Tolerability was comparable between doses. Dexmethylphenidate extended-release 30-mg dose may provide further benefit to patients who do not maintain optimal symptom control later in the day with D-MPH-ER 20 mg.
Trial registration: ClinicalTrials.gov NCT00776009.