Methylphenidate Hydrochloride Modified-Release in Adults with Attention Deficit Hyperactivity Disorder: A Randomized Double-Blind Placebo-Controlled Trial

Introduction

Treatment options for adults with attention deficit hyperactivity disorder (ADHD) are limited. The study was conducted to confirm the clinically effective and safe dose of methylphenidate hydrochloride modified-release (MPH-LA) in adults with ADHD and evaluate the maintenance of effect of MPH-LA.

Methods

The study consisted of three treatment phases. The double-blind dose-confirmation phase: 9-week double-blind period (3-week titration period, 6-week fixed dose) with randomization to MPH-LA 40, 60, or 80 mg/day or placebo. The real-life dose-optimization phase: a 5-week re-titration period to optimal dose; and the double-blind maintenance of effect phase, a 6-month double-blind randomized placebo-controlled maintenance of effect phase. The three co-primary endpoints were change in Diagnostic and Statistical Manual of Mental Disorders-IV ADHD Rating Scale (DSM-IV ADHD RS) and Sheehan Disability Scale (SDS) total scores from baseline to end of 9-week confirmation phase and the percentage of treatment failures during the 6-month maintenance of effect phase.

Results

725 of 863 screened patients were randomized to 40 (N = 181), 60 (N = 182), or 80 mg (N = 181) MPH-LA or placebo (N = 181), and 584 (80.6%) completed. 489 (83.7%) of completers were re-randomized to the double-blinded maintenance of effect phase and 235 (48.1%) of them completed. Improvement from baseline in DSM-IV ADHD RS (P < 0.0001 for all comparisons) and SDS (40 mg, P = 0.0003; 60 mg, P = 0.0176; 80 mg, P < 0.0001) total scores was significantly greater vs. placebo for all MPH-LA doses. Treatment failure rate was significantly lower with MPH-LA (21.3%) versus placebo (49.6%) during the 6-month maintenance of effect phase. Safety profile was consistent with the profile for MPH-LA in children; percentage of serious adverse events was comparable between all MPH-LA arms (1.3%) and placebo (1.5%), while percentage of adverse events was higher in MPH-LA arms.

Conclusion

MPH-LA provided and maintained significant symptomatic and functional improvement in adult ADHD patients.