Osmotic Release Oral System Methylphenidate Versus Atomoxetine for the Treatment of Attention-Deficit/Hyperactivity Disorder in Chinese Youth: 8-Week Comparative Efficacy and 1-Year Follow-Up.

OBJECTIVE

The purpose of this study was to compare the short-term efficacy, tolerability, and 1-year adherence in Chinese children and adolescents with attention-deficit/hyperactivity disorder (ADHD) treated with either osmotic release oral system methylphenidate (OROS MPH) or atomoxetine (ATX).

METHODS

Children and adolescents meeting Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria for ADHD were randomly assigned to receive either OROS MPH (n = 119) or ATX (n = 118). Participants underwent a 1-4 week dose titration period to determine optimal dose, and then were maintained on that dose for 4 weeks (maintenance period). Assessment for efficacy was conducted every week over the titration period and at the end of the maintenance period. The primary efficacy measure was the investigator-rated total ADHD Rating Scale-IV (ADHD-RS-IV) score. Response was further classified as remission (ADHD-RS-IV [18 or 9 items] average score ≤1), robust improvement (ADHD-RS-IV ≥40% decrease in total score), or improvement (≥ 25% decrease in total score) at the end of maintenance period. Medication adherence (taking medication at least 5 days in 1 week) and reasons for nonadherence were evaluated every week over the titration period, at the end of maintenance period, and then at 3, 6, and 12 months.

RESULTS

At the end of maintenance period, both OROS MPH and ATX were associated with significant and similar reductions from baseline in ADHD symptoms. Percentages achieving remission, robust improvement, and improvement were comparable for OROS MPH and ATX treatment (35.3% vs. 37.1%, 45.4% vs. 44.8%, 65.5% vs. 66.4%). Medication use decreased over time for both treatments; however, at end of maintenance period, 3 month, 6 month, and 1 year follow-ups, subjects in the OROS MPH group were more likely to be compliant with treatment (74.8%, 50.4%, 38.7%, and 21.8% for OROS MPH vs. 52.5%, 33.9%, 12.7%, and 3.4% for ATX) ( p < 0.05). The most common reasons for nonadherence were adverse events and lack of efficacy.

CONCLUSIONS

Both OROS MPH and ATX resulted in similar reductions in ADHD symptoms in Chinese children and adolescents with ADHD. Long-term adherence with medication was poor in general, although somewhat better with OROS MPH than with ATX.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , Identifier: NCT01065259.