A non-interventional study of extended-release methylphenidate in the routine treatment of adolescents with ADHD: effectiveness, safety and adherence to treatment.

This multi-centre, open-label, non-interventional study evaluates effectiveness, safety and adherence to treatment of a specific extended-release methylphenidate with a 50 % immediate and a 50 % extended-release component (Medikinet(®) retard) in the clinical routine treatment of 381 adolescents with ADHD and a mean age of 14.0 ± 1.9 years. ADHD and associated psychiatric symptoms, medication status and dosage frequency, treatment adherence and adverse events were assessed at baseline and after a median treatment length with Medikinet(®) retard of 70 days. Primary outcome criterion was the change of ADHD symptom severity from baseline to endpoint according to the ADHD-KGE (German: ADHS-Klinische Gesamteinschätzung) change score. At baseline, 4.2 % of the patients were treatment naïve, 92.7 % had previously received different methylphenidate formulations and 3.1 % had received atomoxetine or amphetamine. During the study, patients received a mean daily dose of 35.7 ± 15.1 mg Medikinet(®) retard. At endpoint, in 78 % of patients, the total ADHD symptom severity was reduced, in 20.4 %, it remained unchanged and in 1.6 %, it was worsened. The mean ADHD-KGE total ADHD symptom score was reduced from 1.8 ± 0.7 (moderate) at baseline to 0.8 ± 0.5 (mild; p < 0.001) at endpoint; the mean ADHD-KGE total-associated symptom score was reduced from 1.9 ± 0.7 (moderate) at baseline to 1.0 ± 0.6 (mild; p < 0.0001) at endpoint. After the medication switch from previous methylphenidate formulation to Medikinet(®) retard, multiple dosing with ≥3 daily medication intakes was reduced from 12.9 % at baseline to 3.1 % at endpoint (p < 0.001). Adherence to treatment was improved in 37 % of patients. Most frequent adverse events were loss of appetite and gastrointestinal problems. The findings suggest that pharmacologically treated adolescents with ADHD and insufficient symptom reduction and/or treatment adherence benefit from switching to Medikinet(®) retard and that it is well tolerated when given in clinical routine care.