Open-Label Study of Dexmethylphenidate Hydrochloride in Children and Adolescents with Attention Deficit Hyperactivity Disorder

BACKGROUND: This pilot study examined the efficacy and duration of the effect of dexmethylphenidate (d-MPH) given once-daily in subjects with attention deficit hyperactivity disorder (ADHD). METHOD: Subjects aged 6-18 years (inclusive) with ADHD were enrolled in this 8-week, openlabel study. Outcome measures included the Conners'Teacher and Parent Rating Scales, the Attention Deficit Disorder Rating Scale (ADDRS), the Clinical Global Impression (CGI) Scale, and teacher and parent visual analog scales to estimate the duration of efficacy. d-MPH was initiated at a dose of 2.5 mg/day. The dose was flexible, based on response and tolerability, and could be increased in increments of 2.5 mg/day to a maximum daily dose of 30 mg/day. RESULTS: Twenty-two subjects (mean age, 8.7 +/- 0.4 years) were treated. Significant improvements (p <0.0001) from baseline occurred in the Conners' Teacher and Parent Rating Scales after 8 weeks. Of the evaluated subjects, 85.7% (18 of 21) showed at least a 30% improvement from baseline on the Conners' Teacher Rating Scale, and 86.4% (19 of 22) of subjects showed at least a 30% improvement from baseline on the Conners' Parent Rating Scale. Most subjects demonstrated an improvement on the ADDRS and the CGI-Improvement (CGI-I) scale. Median duration of effect was estimated at 6.2 hours (teachers) and at 7.5 hours (parents). On average, patients gained 2.4 pounds over the course of the study. CONCLUSIONS: A single daily dose of d-MPH was effective in controlling ADHD in children and was well tolerated. Future studies are needed to confirm these findings and to evaluate chronic dosing with d-MPH.