[Clinical assessment of the effect of switch from immediate-release to extended-release methylphenidate in 181 patients with isolated attention deficit/hyperactivity disorder (AD/HD) or AD/HD associated with pervasive developmental disorder].

We switched medication from conventional immediate-release preparations of methylphenidate to extended-release tablets (an osmotic release oral system) in 165 of 181 cases with attention deficit/hyperactivity disorder (AD/HD), in accordance with the revised indications for these tablets. We investigated the types of developmental disorders, doses of the drug, efficacy, adverse effects, concomitant medication, other relevant problems, and so on, prior to switching the medications. The most common types of developmental disorders were AD/HD with symptoms of pervasive developmental disorder (PDD) and PDD with symptoms of AD/HD. The efficacy evaluation revealed that the extended release tablets had efficacy equivalent to or greater than that of the immediate release preparation. The efficacy rate was 82.7% in our patients. However, cases with difficulty ingesting the tablets, requiring small doses, and those over 18 years of age still seen in the pediatrics department, remained as problematic issues which require further consideration.