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

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.