Objective: This 5-week, multicenter, double-blind, placebo-controlled, parallel-group investigation is the first fixed-dose study to evaluate efficacy and tolerability of three doses of (10, 20, or 30 mg, once daily [o.d.]) dexmethylphenidate hydrochloride (HCl) extended-release (d-MPH XR; Focalin XR) across multiple settings to treat pediatric attention-deficit/hyperactivity disorder (ADHD).
Results: ADHD pediatric outpatients (n = 253) diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, 4(th) edition, criteria were randomized (1:1:1:1) to receive d-MPH XR (10, 20, or 30 mg o.d.) or placebo. Treatment with d-MPH XR significantly (p < 0.001) reduced the mean score (change from baseline) on Conners'-ADHD/DSM-IV Scales (CADS) as assessed by the teacher CADS-T (dose [mean];10 mg [18], 20 mg [16.9], 30 mg [20.7]) and parents, CADS-P (dose [mean];10 mg [15.8]; 20 mg [17.8]; 30 mg [20.5]) compared to placebo (mean CADS-T [5.7]; CADS-P [4.6]). A significant (p < 0.001) proportion of patients in the three d-MPH XR treatment groups showed improvement on the clinician-rated, Clinical Global Impressions-Improvement (CGI-I) scales (10 mg [73.8%]; 20 mg [71.2%]; 30 mg [77.2 %]) and severity ratings (CGI-S) compared to the placebo group (CGI-I, 22.2%). Adverse events were mild to moderate in severity and similar to previous observations for this class of neurostimulants.
Conclusion: All three doses of d-MPH XR (10, 20, or 30 mg o.d), were significantly more effective than placebo in improving ADHD symptoms as confirmed by the teacher, parent and clinician. Additionally, d-MPH XR was well tolerated and demonstrated a consistent safety profile.