Cocaine (from French cocaïne, from Spanish coca, ultimately from Quechua kúka)[13] is a tropane alkaloid that acts as a central nervous system stimulant.

[12] As cocaine also has numbing and blood vessel constriction properties, it is occasionally used during surgery on the throat or inside of the nose to control pain, bleeding, and vocal cord spasm.

[37] In the United States, cocaine is regulated as a Schedule II drug under the Controlled Substances Act, meaning that it has a high potential for abuse but has an accepted medical use.

[38] While rarely used medically today, its accepted uses are as a topical local anesthetic for the upper respiratory tract as well as to reduce bleeding in the mouth, throat and nasal cavities.

[40]Topical cocaine is sometimes used as a local numbing agent and vasoconstrictor to help control pain and bleeding with surgery of the nose, mouth, throat or lacrimal duct.

Although some absorption and systemic effects may occur, the use of cocaine as a topical anesthetic and vasoconstrictor is generally safe, rarely causing cardiovascular toxicity, glaucoma, and pupil dilation.

Rolled up banknotes, hollowed-out pens, cut straws, pointed ends of keys, specialized spoons,[57] long fingernails, and (clean) tampon applicators are often used to insufflate cocaine.

The cocaine typically is poured onto a flat, hard surface (such as a mobile phone screen, mirror, CD case or book) and divided into "bumps", "lines" or "rails", and then insufflated.

An injected mixture of cocaine and heroin, known as "speedball", is a particularly dangerous combination, as the converse effects of the drugs actually complement each other, but may also mask the symptoms of an overdose.

It has been responsible for numerous deaths, including celebrities such as comedians/actors John Belushi and Chris Farley, Mitch Hedberg, River Phoenix, grunge singer Layne Staley and actor Philip Seymour Hoffman.

[81][82] Physical side effects from chronic smoking of cocaine include coughing up blood, bronchospasm, itching, fever, diffuse alveolar infiltrates without effusions, pulmonary and systemic eosinophilia, chest pain, lung trauma, sore throat, asthma, hoarse voice, dyspnea (shortness of breath), and an aching, flu-like syndrome.

[105] Cocaine has a short elimination half life of 0.7–1.5 hours and is extensively metabolized by plasma esterases and also by liver cholinesterases, with only about 1% excreted unchanged in the urine.

Street cocaine is often adulterated or "cut" with cheaper substances to increase bulk, including talc, lactose, sucrose, glucose, mannitol, inositol, caffeine, procaine, phencyclidine, phenytoin, lignocaine, strychnine, levamisole, and amphetamine.

Crack is usually smoked in a glass pipe, and once inhaled, it passes from the lungs directly to the central nervous system, producing an almost immediate "high" that can be very powerful – this initial crescendo of stimulation is known as a "rush".

Urine specimens were also analyzed from an individual who consumed one cup of coca tea and it was determined that enough cocaine and cocaine-related metabolites were present to produce a positive drug test.

[153] Cocaine and its major metabolites may be quantified in blood, plasma, or urine to monitor for use, confirm a diagnosis of poisoning, or assist in the forensic investigation of a traffic or other criminal violation or sudden death.

Indigenous peoples of South America have chewed the leaves of Erythroxylon coca—a plant that contains vital nutrients as well as numerous alkaloids, including cocaine—for over a thousand years.

The remains of coca leaves have been found with ancient Peruvian mummies, and pottery from the time period depicts humans with bulged cheeks, indicating the presence of something on which they are chewing.

[173] In 1856, Friedrich Wöhler asked Dr. Carl Scherzer, a scientist aboard the Novara (an Austrian frigate sent by Emperor Franz Joseph to circle the globe), to bring him a large amount of coca leaves from South America.

He wrote of the alkaloid's "colourless transparent prisms" and said that "Its solutions have an alkaline reaction, a bitter taste, promote the flow of saliva and leave a peculiar numbness, followed by a sense of cold when applied to the tongue."

[185] The company promised that its cocaine products would "supply the place of food, make the coward brave, the silent eloquent and render the sufferer insensitive to pain."

[186] In 1909, Ernest Shackleton took "Forced March" brand cocaine tablets to Antarctica, as did Captain Scott a year later on his ill-fated journey to the South Pole.

[189] During the mid-1940s, amidst World War II, cocaine was considered for inclusion as an ingredient of a future generation of 'pep pills' for the German military, code named D-IX.

[195] In 1995 the World Health Organization (WHO) and the United Nations Interregional Crime and Justice Research Institute (UNICRI) announced in a press release the publication of the results of the largest global study on cocaine use ever undertaken.

An excerpt of the report strongly conflicted with accepted paradigms, for example, "that occasional cocaine use does not typically lead to severe or even minor physical or social problems."

[203] A problem with illegal cocaine use, especially in the higher volumes used to combat fatigue (rather than increase euphoria) by long-term users, is the risk of ill effects or damage caused by the compounds used in adulteration.

[223] Attempts to eradicate coca fields through the use of defoliants have devastated part of the farming economy in some coca-growing regions of Colombia, and strains appear to have been developed that are more resistant or immune to their use.

[229][230] Synthesizing cocaine could eliminate the high visibility and low reliability of offshore sources and international smuggling, replacing them with clandestine domestic laboratories, as are common for illicit methamphetamine, but is rarely done.

While the price of cocaine is higher in Chile than in Peru and Bolivia, the final destination is usually Europe, especially Spain where drug dealing networks exist among South American immigrants.

According to the Summer 1998 Pulse Check, published by the U.S. Office of National Drug Control Policy, cocaine use had stabilized across the country, with a few increases reported in San Diego, Bridgeport, Miami, and Boston.