Abstract
Attention-deficit hyperactivity disorder (ADHD) is the most commonly diagnosed psychiatric disorder in children and adolescents in the United States. In 2016, approximately 3.8 million U.S. children ages 2 to 17 years with ADHD were being treated with medication. There are approximately 30 different amphetamine (AMPH) and methylphenidate (MPH) formulations on the market. These include immediate-release and extended-release compounds. The extended-release formulations contain various ratios of immediate-release and extended-release components, which determine the pharmacokinetic (PK) profile. For stimulants, the PK and pharmacodynamic (PD) profiles are tightly linked, and the immediate-release and extended-release percentages influence onset and duration of drug effects. Choosing the right stimulant medication for a patient depends on an understanding of the PK/PD profile, the time of day that symptoms are most impairing, the need for morning and evening symptom control and individual patient preferences.