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 ability to pay attention, stay focused on an activity, and control behaviour problems. It may also help you to organize your tasks and improve listening skills. This drug is also used to treat a certain sleeping disorder (narcolepsy) to help you stay awake during the day. It should not be used to treat tiredness or to hold off sleep in people who do not have a sleep disorder.