Celgene has developed a chirally pure form of methylphenidate (Ritalin), called dexmethylphenidate [d-methylphenidate, d-methylphenidate hydrochloride, d-MPH; Focalin]. The drug has been launched in the USA and is undergoing registration in Canada for the treatment of children with attention-deficit hyperactivity disorder (ADHD). Dexmethylphenidate is the single isomer version of racemic methylphenidate (Ritalin), which contains the active d isomer of Ritalin. Dexmethylphenidate acts via the inhibition of reuptake of norepinephrine and dopamine. Research is ongoing to further clarify the mode of therapeutic action in ADHD. Dexmethylphenidate was developed with the aim of reducing drug load, adverse events and drug interactions. Dexmethylphenidate provides effective management of attention-deficit hyperactivity disorder at half the dose of Ritalin. In April 2000, worldwide rights (excluding Canada) to dexmethylphenidate were granted to Novartis. Celgene has also granted Novartis rights to all related intellectual properties and patents. Novartis will fund all remaining development and marketing expenses required for regulatory approval and commercialisation of dexmethylphenidate. Crystaal Corporation, the marketing division of Biovail Corporation International, has exclusive Canadian marketing rights for all formulations of dexmethylphenidate. Novartis launched dexmethylphenidate (Focalin) in the USA during Q1 2002. It is available as a D-shaped tablet (2.5, 5 and 10 mg doses). Novartis had planned to use the tradename Ritadex, however the FDA recommended an alternative name due to potential prescribing errors with Ritalin. The finalized tradename to be used is Focalin. In July 2001, a new drug submission was filed with Canada's Therapeutic Products Programme for dexmethylphenidate in the treatment of attention-deficit disorder and attention-deficit hyperactivity disorder. Novartis is also developing an extended-release version of chirally pure dexmethylphenidate. Dexmethylphenidate has been found to be effective and well tolerated in clinical trials, involving a total of 684 children with ADHD and in 15 healthy adult volunteers. Dexmethylphenidate is a schedule II drug.