Cocaine molecule. Computer artwork of a molecule of the drug cocaine. Cocaine is an alkaloid drug obtained from the leaves of the coca plant (Erythoxylon coca). It acts as a local anaesthetic, although its use for this purpose has declined due to the availability of less toxic alternatives. It is also used as a recreational drug. It can be smoked, injected or snorted, producing feelings of exhilaration and energy due to its stimulating action on the central nervous system. Prolonged use of cocaine can lead to anxiety, paranoia and dependency. Overdosing can result in irregular heartbeat and death.