cocaine, white crystallinealkaloid that is obtained from the leaves of thecoca plant (Erythroxylum coca), a bush commonly found growing wild inPeru,Bolivia, and Ecuador andcultivated in many other countries. Thechemical formula of cocaine is C₁₇H₂₁NO₄. Cocaine acts as ananesthetic because it interrupts the conduction of impulses in nerves, especially those in themucous membranes of the eye, nose, and throat. More importantly, cocaine when ingested in small amounts produces feelings of well-being and euphoria, along with a decreased appetite, relief from fatigue, and increased mental alertness. When taken in larger amounts and upon prolonged and repeated use, cocaine can produce depression,anxiety, irritability, sleep problems, chronic fatigue, mental confusion,paranoia, and convulsions that can cause death.

For centuries the Indians of Peru and Bolivia have chewed coca leaves mixed with pellets oflimestone or plant ashes for pleasure or in order to withstand strenuous working conditions, hunger, and thirst. In othercultures the active alkaloid is chemically extracted from coca leaves and is converted into the hydrochloric salt of cocaine, cocaine hydrochloride. This fine white powder is sniffed through a hollow tube and is readily absorbed into the bloodstream through the nasal mucous membranes. Cocaine is an irritant, however, and acts to constrict blood vessels, causing a chronic runny nose or, in severe cases, ulcerations in the nasal cavity. The euphoric effects of sniffing cocaine are relatively transitory and wear off after about 30 minutes. Cocaine is habit-forming and may also be physically addicting. Cocaine is also injected in solution or smoked in a chemically treated form known asfreebase; either of these methods produces a markedly more compulsive use of thedrug. In the 1980s a new preparation of cocaine appeared, calledcrack; the smoking of crack produces an even more intense and even more short-lived euphoria that is extremelyaddicting. This form of cocaineconsumption is also the one mostdetrimental tohealth. Another smokable and highly addictive form is cocaine paste, which is an intermediate stage in the processing of coca leaves into cocaine.

The prolonged orcompulsive use of cocaine in any of its purified forms can cause severe personality disturbances, inability to sleep, and loss of appetite. A toxicpsychosis can develop involving paranoiddelusions and disturbingtactile hallucinations in which the user feels insects crawling under his skin. Cocaine abuse, which had been a marginal drug problem throughout much of the 20th century, grew alarmingly in the late 20th century in several countries, and cocaine has become responsible for a markedly increased proportion of drug-induced deaths.

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