Abstract

Treatment effectiveness between equivalent doses of non-OROS (osmotic controlled release oral delivery system) methylphenidate ER and OROS methylphenidate ER (brand name Concerta) was examined in a clinical case series of children and adolescents followed for treatment of attention-deficit/hyperactivity disorder (ADHD). The Conners-Third Edition: Parent Rating Scale was used to compare ADHD symptoms when patients were taking non-OROS versus OROS at follow-up visits. A repeated-measures mixed-model approach was used to compare treatment effectiveness. The entire sample (N = 14) demonstrated a reduction in the mean score on the Inattention Scale from clinically significant (T-score > 65) to not clinically significant (T-score < 65) when patients were changed from non-OROS to OROS at the same dosage (mean T-score reduction = 23, p < .0001). The reduction in mean T-score after changing from non-OROS to OROS at the same dosage is indicative of improvement in symptoms of ADHD. Results provide empirical support for US Food and Drug Administration concerns regarding the therapeutic equivalence of non-OROS versus OROS for the treatment of ADHD.