Azstarys (serdexmethylphenidate and dexmethylphenidate) is a central nervous system (CNS) stimulant for the treatment of ADHD in patients 6 years of age and older. It is usually taken once per day. Adderall (mixed amphetamine salts) is also a CNS stimulant for the treatment of ADHD, but is used in patients 3 years of age and older and is usually given 2 or 3 times per day.