While studies have established efficacy and safety of short-term treatment with methylphenidate for attention-deficit/hyperactivity disorder (ADHD), data during long-term treatment have been sparse. This two-year study was designed to gather data on long-term usage of a once-daily methylphenidate hydrochloride formulation among school-age children.

　

Characteristics of study design and participants ・ Multicenter, open-label trial ・ Once-daily dosing for up to 24 months of follow-up ・ Efficacy rated by parents and teachers monthly during the first year and every three months afterward ・ Adverse effects, tics, and sleep quality reported by parents ・ Vital signs monitored throughout study period by investigators ・ 407 children, 6 to 13 years of age, all of whom had been enrolled in a previous short-term, controlled study of the same drug formulation

Outcome measures confirmed that effectiveness of once-daily methylphenidate during long-term treatment was similar to that seen in the same children during short-term treatment. Perhaps of greatest interest for clinicians and parents was the finding that health and development did not appear to be adversely affected by long-term treatment with methylphenidate.

　

Health and development measures that remained within normal limits during long-term treatment ・ Blood pressure and pulse rate ・ Red and white blood cell counts ・ Liver function tests ・ Growth (height and weight)

Moreover, long-term treatment with methylphenidate was not associated with induction or worsening of tics or unusual or unexpected adverse effects.

Wilens and colleagues conclude from their findings that long-term treatment with a once-daily formulation of methylphenidate is both effective and safe for children with attention-deficit/hyperactivity disorder

(abstract Session 15 No. 44)