New Formulations of Stimulants: An Update for Clinicians.

In the last 15 years, there has been a marked increase in the number of available stimulant formulations with the emphasis on long-acting formulations, and the introduction of several novel delivery systems such as orally dissolving tablets, chewable tablets, extended-release liquid formulations, transdermal patches, and novel "beaded" technology. All of these formulations involve changes to the pharmaceutical delivery systems of the two existing compounds most commonly employed to treat attention-deficit/hyperactivity disorder (ADHD), amphetamine (AMP) and methylphenidate (MPH). In addition to these new formulations, our knowledge about the individual differences in response has advanced and contributes to a more nuanced approach to treatment. The clinician can now make increasingly informed choices about these formulations and more effectively individualize treatment in a way that had not been possible before. In the absence of reliable biomarkers that can predict individualized response to ADHD treatment, clinical knowledge about differences in MPH and AMP pharmacodynamics, pharmacokinetics, and metabolism can be utilized to personalize treatment and optimize response. Different properties of these new formulations (delivery modality, onset of action, duration of response, safety, and tolerability) will most likely weigh heavily into the clinician's choice of formulation. To manage the broad range of options that are now available, clinicians should familiarize themselves in each of these categories for both stimulant compounds. This review is meant to serve as an update and a guide to newer stimulant formulations and includes a brief review of ADHD and stimulant properties.