This combination medication is used to treat attention deficit hyperactivity disorder – ADHD. It works by changing the amounts of certain natural substances in the brain. Amphetamine/dextroamphetamine belongs to a class of drugs known as stimulants. It can help increase your focus, stay focused on an activity, and control behavioral problems. It can also help you organize your tasks and improve your listening skills. This drug is also used to treat a certain sleep disorder (narcolepsy) to keep you awake during the day. It should not be used to treat fatigue or to delay sleep in people who do not have a sleep disorder.