Dexmethylphenidate extended release: a review of its use in the treatment of attention-deficit hyperactivity disorder.

Dexmethylphenidate extended release (XR) [Focalin XR] is a CNS stimulant indicated for the treatment of attention-deficit hyperactivity disorder (ADHD) in patients aged > or = 6 years. Dexmethylphenidate contains the d-threo-enantiomer of methylphenidate. Dexmethylphenidate XR capsules have a bimodal release profile, which mimics two doses of dexmethylphenidate immediate release (IR) given 4 hours apart, and allows once-daily administration. Once-daily dexmethylphenidate XR was effective and generally well tolerated in the treatment of ADHD in children, adolescents and adults in placebo-controlled trials. Improvements in ADHD symptoms were significantly greater for dexmethylphenidate XR versus placebo throughout the day, from as early as 0.5 hours after drug administration up to 11-12 hours after administration. Furthermore, dexmethylphenidate XR showed greater efficacy than osmotic release oral system (OROS) methylphenidate over the first half of the laboratory classroom day in crossover trials; however, assessments late in the day (10-12 hours post-dose) favoured OROS methylphenidate. The once-daily administration regimen with dexmethylphenidate XR avoids the need for a midday dose to be administered at school; administration options are extended in that the contents of the dexmethylphenidate XR capsule can be sprinkled on apple sauce for patients unable to swallow the capsule whole. Although dexmethylphenidate XR is a controlled substance in the US, this formulation appears to have a low risk of abuse or misuse. Thus, dexmethylphenidate XR extends the range of first-line pharmacological treatment options for children, adolescents or adults with ADHD, particularly for patients who require a rapid onset and prolonged duration of action, including children who require a reduction in ADHD symptoms throughout the school day.