A randomized, single-blind, substitution study of OROS methylphenidate (Concerta) in ADHD adults receiving immediate release methylphenidate

Abstract

Objective: The main aim of this study was to examine the efficacy, tolerability, and compliance of an extended-release formulation of methylphenidate (OROS-MPH) in adults with ADHD receiving immediate-release methylphenidate (IR-MPH).

Method: Participants were outpatient adults with ADHD who were stable on IR-MPH-administered TID. Participants were randomized (4:1) to equipotent doses of OROS-MPH or to continue IR-MPH and were assessed weekly for 6 weeks with the Adult ADHD Investigator System Symptom Report Scale (AISRS).

Results: Randomization of 53 IR-MPH responders to IR- or OROS-MPH had no effect on AISRS score at endpoint (11.2 ± 6.9 vs. 10.7 ± 5.1, p = .8). Participants stabilized on IR-MPH and switched to OROS-MPH remained satisfied over 71% of the time. However, the IR-MPH group missed more doses (7.3 ± 6.8 vs. 3.3 ± 4.2, p = .02) than the OROS-MPH group.

Conclusion: Findings showed that adults with ADHD can be successfully switched from an effective regimen of IR-MPH TID to once-daily OROS-MPH. Results also demonstrated better compliance with OROS-MPH than with IR-MPH treatment.