Titrating Optimal Dose of Osmotic-Controlled Release Oral Delivery (OROS)-Methylphenidate and Its Efficacy and Safety in Korean Children with ADHD: A Multisite Open Labeled Study

Abstract

Objective This study was aimed to determine effectiveness and tolerability of Osmotic-controlled Release Oral delivery (OROS) methylphenidate (MPH) and its optimal dose administered openly over a period of up to 12 weeks in drug naive Korean children with ADHD. Methods Subjects (n=143), ages 6 to 18-years, with a clinical diagnosis of any subtype of ADHD were recruited from 7 medical centers in Korea. An individualized dose of OROS-MPH was determined for each subject depending on the response criteria. The subjects were assessed with several symptom rating scales in week 1, 3, 6, 9 and 12. Results 77 of 116 subjects (66.4%) achieved the criteria for response and the average of optimal daily dose for response was to 30.05 +/- 12.52 mg per day (0.90 +/- 0.31 mg/kg/d) at the end of the study. Optimal dose was not significantly different between ADHD sub-types, whereas, significant higher dose was needed in older aged groups than younger groups. The average of optimal daily dose for response for the subjects aged above 12 years old was 46.38 +/- 15.52 per day (0.81 +/- 0.28 mg/kg/d) compared to younger groups (p<0.01). No serious adverse effects were reported and the dose did not have a significant effect on adverse effects. Conclusion Optimal mean dose of OROS-MPH was significantly different by age groups. Higher dose was needed in older aged groups than younger groups. Effectiveness and tolerability of OROS-MPH in symptoms of ADHD is sustained for up to 12 weeks. Psychiatry Investig 2012;9:257-262