The efficacy and safety of dexmethylphenidate extended release (d-MPH-ER) was compared to placebo in 97 patients (ages 6-17 years) with attention-deficit/hyperactivity disorder (ADHD) in a multicenter, randomized, double-blind, two-phase study reported from New York State Psychiatric Institute, New York. The once daily dose of d-MPH-ER was flexible (5-30 mg/kg) for 5 weeks, and the patients’ final optimal dose (mean, 24.0 +/- 7.1 mg/day) was maintained during the last 2 weeks of the 7-week trial. Conners ADHD/DSM-IV Scale-Teacher version (CADS-T) total score improved significantly compared with placebo (p<.001), and 67.3% of patients were much improved on a Clinical Global Impressions-Improvement (CGI-I) Scale at final visit versus 13.3% of placebo patients (p<.001). Drug-related adverse events were spontaneously reported by 49.1% patients taking d-MPH-ER vs 25.5% of placebo-treated patients (p=.01). Decreased appetite was drug- related in 28.3%, headache in 9.4%, and insomnia in 7.5%. No patient discontinued the drug because of adverse events. 
COMMENT. At a mean daily dose of 24 mg/day, d-MPH-ER was significantly superior to placebo in the treatment of ADHD. The mean dose of d-MPH-ER found effective is equivalent to a 50 mg/day dose of racemic methylphenidate.