Osmotic, controlled-release methylphenidate for the treatment of ADHD.

Methylphenidate (MPH) is the most commonly used and best-studied stimulant medication for attention-deficit hyperactivity disorder. However, its short duration of action usually results in a requirement to administer multiple daily doses in order to achieve optimal clinical benefit. Although a wax-matrix-based SR formulation of MPH has been available since the 1990s, it was not well accepted into clinical practice. The variable absorption profile and lack of an immediate-release component results in a slower onset of action compared with immediate-release MPH. Hence, there was a need to develop alternative longer-lasting preparations of MPH that were as efficacious as IR MPH, but which also addressed the problems inherent in multiple daily dosing. An osmotic, controlled-release (OROS) formulation of MPH HCl has been developed over the past 10 years for once-daily administration. OROS MPH has been widely accepted by clinicians and is now the most widely prescribed MPH product in North America. Clinical trials have shown OROS MPH to have a continued action over a 12-h period, to be superior to placebo and to be as effective as immediate-release MPH dosed three times daily, in reducing symptoms of attention-deficit hyperactivity disorder, with similar incidence of side effects. There have been a smaller number of trials comparing OROS MPH with non-stimulant treatments, such as atomoxetine.