A randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy and safety of osmotic-controlled release oral delivery system methylphenidate HCl in adults with attention-deficit/hyperactivity disorder in Japan.
OBJECTIVES
To evaluate the safety and efficacy of osmotic-controlled release oral delivery system (OROS) methylphenidate (MPH) HCl in adults with attention-deficit/hyperactivity disorder (ADHD).


METHODS
In this study, 284 adults with ADHD were randomized to OROS MPH or placebo. During the 4-week titration period, patients were titrated from a starting dose of 18 mg once daily to an individually-optimized dose of up to 72 mg once daily in weekly 18-mg increments. Patients continued on their individualized dose during the 4-week efficacy assessment period. The primary efficacy endpoint was change in DSM-IV Total ADHD Symptoms subscale score of Conners' Adult ADHD Rating Scale-Observer: Screening Version (CAARS-O:SV) from baseline to endpoint.


RESULTS
The mean change in DSM-IV Total ADHD Symptoms subscale score of CAARS-O:SV was significantly larger with OROS MPH compared with placebo (P < 0.0001, ANCOVA). Similar results were observed for the majority of secondary endpoints, including CAARS-O:SV total score and other subscale scores. Although treatment-emergent adverse events were reported more frequently in the OROS MPH group (81.8%) versus the placebo group (53.9%), OROS-MPH showed a well-tolerated safety profile overall.


CONCLUSIONS
OROS MPH in a dose range of 18-72 mg once daily was effective and well-tolerated in adult patients with ADHD.