Cocaine



Cocaine is a powerful drug of the stimulant-euphoriant class that is obtained from an alkaloid in the leaves of the coca plant, a shrub or tree that grows in the South American countries of Peru and Bolivia. The processed drug is a white, crystalline compound called benzoylmethylecgonine. It is a central nervous system stimulant, which means it temporarily produces euphoria (a feeling of well-being), prevents drowsiness and fatigue, increases physical energy, heart rate and body temperature, decreases appetite, and increases talkativeness. Cocaine can also cause the user to become irritable, and have hallucinations (strange visions). An overdose of cocaine can cause trembling, vomiting, convulsions, and a depression of the central nervous system. This depression can cause breathing to stop or heart failure. Because it is so highly addictive, cocaine is classified as a narcotic and is controlled by federal drug abuse laws in the United States.

The Indians of South America have chewed the leaves of the coca plant for many generations to help them overcome fatigue and hunger, stay alert, and have greater stamina in the high elevations of the Andes Mountains; the leaves also numb the mouth and stomach. Coca leaves were chewed by Inca runners who carried messages long distances over the mountains and probably by workers who built the Inca road system. Many pottery figurines of early South America show men and women chewing coca leaves, often with expressions of great pleasure on their faces.

Early Research

Albert Niemann (1880-1921) separated the alkaloid cocaine from the dried leaves of the coca plant in 1860. He studied the white powder and named it cocaine, also noting the temporary numbing effect the compound had on his tongue. During the 1880s in Vienna, Austria, Sigmund Freud (1856-1939) studied cocaine as a treatment for morphine addiction. Freud suggested the possible use of cocaine as a local anesthetic to Viennese colleagues Leopold Königstein, a professor of ophthalmology (the medical study of the eye and diseases of the eye), and Carl Koller (1857-1944), a young ophthalmologist (doctor specializing in eye diseases).

Koller experimented on animals and then presented his findings to the Congress of Ophthalmology in Heidelberg, Germany, in 1884. He demonstrated the successful use of cocaine as a local anesthetic during eye surgery. Koller's findings were accepted enthusiastically. Koller himself emigrated to the United States in 1888 and established practice in New York City, where he died in 1944. Cocaine was used widely for ophthalmological procedures until it was discovered that it causes damage to the cornea (the transparent part of the eye that covers the iris and the pupil). This combined with its potential for drug abuse has resulted in cocaine's being used today only as a topical (given for one part of the body) anesthetic, mainly in the upper respiratory passages (nose and throat).

Local Anesthesia

American doctor William Halsted soon followed up on Koller's work by experimenting with cocaine injection into nerves to produce local anesthesia. By the end of 1885, Halsted had performed over 1,000 operations using cocaine as an anesthetic. Unfortunately, Halsted also discovered another of cocaine's properties. He became addicted to the substance and spent many years overcoming his dependence. Harvey Cushing (1869-1939), a student of Halsted's, coined the term "regional anesthesia" for this use of cocaine, in contrast to the "general anesthesia" produced by ether, a gas formerly used for anesthesia in surgery. Later in 1855, Leonard Corning (1855-1939), a New York neurologist, injected a cocaine solution as a spinal anesthesia. German doctor Carl L. Schleich (1859-1922) of Berlin used a cocaine solution for infiltration anesthesia in 1892.

Cocaine and Addiction

For many years, the addictive properties of cocaine went unrecognized. As a pain reliever and stimulant, the drug was a common ingredient in the very popular patent medicines of the late 1800s and early 1900s. Doctors freely prescribed cocaine for any number of ailments. Once the addictive dangers became known, scientists concentrated on developing synthetic substitutes for the anesthetic properties of cocaine. One of the first of these was Novocain. Today cocaine is only occasionally used medically, as a local anesthetic applied to the surface of the skin for some kinds of surgery. It is not prepared for internal use or for injection as medicine.

Today most cocaine is purchased and used illegally. Cocaine hydrochloride, a dry white powder also called "coke" or "snow" is often inhaled ("snorted") through a thin tube or straw inserted into the nostril. It is absorbed into the bloodstream through the nasal (nose) mucous membranes. Cocaine is sometimes injected into a vein and sometimes smoked in a purified form through a water pipe, called "freebasing." The most potent form of cocaine, "crack," is shaped into pellets and smoked using special equipment. The widespread use of cocaine and the resulting increase in violence associated with drug dealing was an important factor in stimulating the "war on drugs" in the United States that has continued since the 1980s, when cocaine abuse was at its peak.

Long-term use of cocaine can lead to skin sores, damage to the septum of the nose, weight loss, and damage to the nervous system. Bad mental effects include restlessness, anxiety, irritability, and sometimes paranoid psychosis. When a person stops using cocaine, he or she will experience craving for the drug, long periods of sleep, depression, fatigue, and exhaustion. Because withdrawal from cocaine does not produce extreme and dangerous physical symptoms like those caused by withdrawal from barbiturates, doctors consider cocaine to be more psychologically addictive than physically addictive.

[See also Anesthesia ]



User Contributions:

Hevi Daniel
Report this comment as inappropriate
Mar 15, 2013 @ 2:02 am
is cocaine still used as a local anaesthetic agent?

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