Modafinil: An oral drug first approved by the FDA in 1998 for the treatment of narcolepsy, a condition in which there is an uncontrollable desire to sleep. Modafinil promotes wakefulness. In 2004 the FDA also approved modafinil for the treatment of obstructive sleep apnea and sleeping problems caused by shift work.
Modafinil is said to be in common "off-label" use by college students, truckers, and others who want to stay awake when normally they should be sleeping. The drug is reportedly also being prescribed for numerous other problems including fatigue, depression, multiple sclerosis, and ADHD (attention deficit hyperactivity disorder). Some of these "off-label" uses may prove legitimate while others may be abuses of the drug.
Modafil stimulates the brain without producing the jitteriness of caffeine or the addiction and euphoria of amphetamines. Modafinil is believed to act by affecting dopamine and other neurotransmitters including histamine and norepinephrine. It is sold under the brand name Provigil.