methylphenidate
n. a stimulant related to the amphetamines and with a similar mechanism of action. It is an indirect agonist of catecholamine neurotransmission, blocking the reuptake of catecholamines from the synaptic cleft and stimulating presynaptic release of catecholamines. Unlike amphetamine, methylphenidate is more potent as a reuptake blocker than as a releasing agent. Methylphenidate is used as an adjunct to antidepressant therapy and to increase concentration and alertness in patients with brain injuries, brain cancer, or dementia. It is approved by the U.S. Food and Drug Administration for the treatment of attention-deficit/hyperactivity disorder (ADHD) and narcolepsy in both children and adults. In children with ADHD, methylphenidate increases attention and decreases impulsivity and physical overactivity, leading to improvement in academic and social functioning, at least while the drug is being administered. Potential long-term side effects
include growth suppression, which may occur at least transiently in some children taking these drugs. It is not recommended to use methylphenidate or other stimulants in children without concurrent behavioral therapy or counseling. Methylphenidate has been used off-label by students and long-haul drivers to enhance attention and decrease fatigue. It is classified by the U.S. Drug Enforcement Administration as a Schedule II controlled substance (see scheduled drug). U.S. trade names (among others): Concerta; Metadate; Ritalin.