Dexmethylphenidate.

Dexmethylphenidate comprises only the d-enantiomer (the pharmacologically effective isomer) of racemic methylphenidate and is indicated for the treatment of patients aged > or =6 years with attention deficit hyperactivity disorder (ADHD). In a 4-week, double-blind trial in 132 children with ADHD, significantly greater improvements from baseline in teacher-rated Swanson, Nolan and Pelham (SNAP)-ADHD scores were seen in dexmethylphenidate and methylphenidate recipients, compared with placebo recipients. In addition, significantly more dexmethylphenidate and methylphenidate recipients, compared with placebo recipients, were much improved or very much improved according to Clinical Global Impression-Improvement of Illness scale scores. In the same study, parent-rated SNAP-ADHD scores had decreased by a significantly greater extent in dexmethylphenidate recipients at 3pm and 6pm and in methylphenidate recipients at 3pm, compared with placebo recipients. Significantly fewer dexmethylphenidate than placebo recipients failed treatment in a double-blind, treatment-withdrawal trial in 75 children with ADHD (17.1 vs 61.5%). In a noncomparative study in 22 children with ADHD, symptoms of ADHD, as assessed by teachers and parents, were controlled during the entire school day in 68 and 86% of dexmethylphenidate recipients, respectively, with a median duration of effect of 6.3 and 7.5 hours, respectively. Dexmethylphenidate was generally well tolerated in children with ADHD; adverse events were consistent with those known to be associated with agents containing methylphenidate.