are drugs that temporarily increase alertness and awareness. They usually have increased side-effects with increased effectiveness, and the more powerful variants are therefore often prescription medicines or illegal drugs.

are substances that mimic the effects of the hormone epinephrine (adrenaline) and the hormone/neurotransmitter norepinephrine (noradrenaline). Such drugs raise blood pressure and are weak bases.

is the property of rotating plane polarized light clockwise. Laevorotation is the opposite of dextrorotation.

is a neurological condition most characterized by Excessive Daytime Sleepiness (EDS). A narcoleptic will most likely experience disturbed nocturnal sleep, which is often confused with insomnia, and disorder of REM or rapid eye movement sleep. It is one of the dyssomnias. A narcoleptic may also fall asleep at any random time.

are compounds with the same molecular formula but different structural formulae. Isomers do not necessarily share similar properties unless they also have the same functional groups. This should not be confused with a nuclear isomer, which involves a nucleus at different states of excitement. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical isomers, et cetera (see graph below).

is a brand of methamphetamine hydrochloride (also known as desoxyephedrine, hence the name "Desoxyn"), indicated for treatment of Attention Deficit/Hyperactivity Disorder (ADHD), narcolepsy, and exogenous obeity. Desoxyn is a Schedule II medication under the U.S. DEA Schedule system.