Dexmethylphenidate extended-release capsules in children with attention-deficit/hyperactivity disorder.
OBJECTIVE
This study compared once-daily dexmethylphenidate extended release (D-MPH-ER) 20 mg/day and placebo over 12 hours in children ages 6 to 12 with attention-deficit/hyperactivity disorder (ADHD) in a laboratory classroom setting.


METHOD
All of the children were stabilized for > or =2 weeks on a total dose (nearest equivalent) MPH 40 mg/day or immediate-release D-MPH 20 mg/day before screening. After a practice day, they received 6 days of D-MPH-ER 20 mg/day or placebo at home, returning on day 7 for one dose. Subjects were evaluated at predose and postdose hours 0.5, 1, 3, 4, 5, 7, 9, 10, 11, and 12 and then crossed over to the other treatment arm using the identical protocol. The primary efficacy variable was the change from predose in Swanson, Kotkin, Agler, M-Flynn, and Pelham rating scale (SKAMP) combined score from 1 to 12 hours. Secondary efficacy variables included SKAMP combined score at 0.5 hours, SKAMP subscale scores, and math test results over 12 hours.


RESULTS
Sixty-eight children were randomized, with 67 completing the study. Onset of action was indicated by a significant difference between D-MPH-ER and placebo at 0.5 hour on the SKAMP combined score (p = .001). For efficacy measures, differences from placebo were significant at all points between 0.5 and 12 hours (p < .001 top = .013).


CONCLUSIONS
D-MPH-ER provided sustained improvement in attention, deportment, and academic productivity throughout the 12-hour laboratory day.