[Does a morning dose of Methylphenidate Retard reduce hyperkinetic symptoms in the afternoon?]

Abstract

Objectives: In order to treat children with Attention-deficit/Hyperactivity Disorder (ADHD) with a once-a-day stimulant several galenic approaches have been tried. The long acting methylphenidate (MPH, Medikinet-Retard) is a preparation with a two-step dynamic to release MPH (step one: acute; step two: prolonged). The efficacy of Medikinet-Retard, a new long-acting methylphenidate preparation, is analyzed based on the assessment of parents in the afternoon.

Methods: In a multicenter drug treatment study (placebo controlled, randomized, double-blind) 85 children (normal intelligence, age 6 to 16 years, diagnosis of ADHD according to DSM-IV) were investigated over 4 weeks with weekly visits. Forty-three children received Medikinet-Retard and forty-two children placebo. The weekly dose titration depending on body weight and symptomatology allowed a final maximum of 60 mg. The effects on ADHD as perveived by the parents were assessed weekly with a German symptom checklist for ADHD according to DSM-IV and ICD-10 (FBB-HKS). The differences between baseline and last week of treatment were compared statistically between groups.

Results: There was a large and statistically significant positive drug effect on ADHD symptomatology. The effect size of these differences was d = 1.2 (total score). Effects were found on inattention, hyperactivity and impulsity on the respective subscales. The efficacy of Medikinet-Retard was evaluated by the parents on an average as good. The rate of responders was four-times higher in the verum-group. The correlations of the changed scores in the parent ratings with the respective change scores in the teacher ratings were in the medium range.

Conclusion: This is the first study with a German long-acting methylphenidate preparation (Medikinet-Retard). According to data based on parents' assessments, the drug showed very good clinical efficacy and safety in children with ADHD. Its two step galenic release of methylphenidate seems to be appropriate for a once-a-day (morning) stimulant in schoolchildren.