Реферат: Cocaine

Cocaine…Why? Essay, Research Paper

Why use cocaine? This is a question that perplexes many doctors of medicine and psychology. As an ex user, I feel that this topic is one that I have a personal interest in. I will start by defining what cocaine is. Cocaine is a colorless or white crystalline powder extracted from coca leaves, occasionally used in medicine as a local anesthetic especially for the eyes, nose, or throat and widely used as an illicit drug for its euphoric and stimulating effects. It is a naturally occurring substance derived from the leaves of erythroxylon plants. Cocaine is the world’s most powerful and potent CNS stimulant from natural origin. Plants grown at different altitudes produce different levels of the alkaloid. The higher in elevation, the more cocaine is produced. The coca plant is resistant to drought and disease and needs no irrigation. Only two of the seventeen species yield sufficient levels of the cocaine alkaloid to justify mass cultivation for processing into cocaine. These two species, cultivated primarily in Peru, Bolivia, and Columbia, supply the world’s cocaine. It also can be harvested four times a year.

Coca leaves have been used before recorded history by South American Indians, so the knowledge is derived totally from archaeological sources. Chewing coca leaves has been associated historically with the religious ceremonies of the Incas and reserved specifically for nobility. The coca plant was considered to be a gift from the gods and it was only used during religious rituals, burials, and other special purposes. By the time the Spaniards arrived in the 16th century, the Incan empire was in decline and the use of the leaves was widespread throughout the empire. The Spaniards tried to prevent the Indians from using the leaves because they believed it was a barrier to conversion to Christianity. Later they paid the Indians with the leaves. It was discovered that the leaves reduced mountain sickness symptoms and they could barely work without them. So it came to be cultivated by the Catholic Church. Returning Spanish conquistadors introduced it to Europe and it was considered an “elixir of life”. In 1862, Albert Niemann extracted purified cocaine from a coca base from the coca leaves. In the 1880’s and 1890’s cocaine was in many elixirs and highly regarded. It was an ingredient in cigars, cigarettes, chewing gum, and several “tonics”, most notably Coca Cola. Coca-Cola advertised itself as “the drink that relieves exhaustion”. Pope Leo XII, Sherlock Holmes, Thomas Edison, Jules Verne, and Sigmund Freud all endorsed its use. Freud described it as a magical drug. He wrote a song of praise in its honor and practiced self-experimentation. Sherlock Holmes said that cocaine was so transcendentally stimulating and clarifying to the mind that its secondary action is a matter of small moment. Doctors also prescribed cocaine as an antidote to morphine addiction. The abuse of cocaine in the United States was largely non-existent until the 1960’s, except among jazz musicians and entertainers.

Cocaine can be processed into four different forms. I am only going to talk about the most predominate one, powdered cocaine. The traditional method of taking cocaine in the West involved “snorting” or insufflating the drug through a thin straw into the mucous membranes of the nasal cavity. It is absorbed into the bloodstream from there. This is not the most efficient route of administering cocaine since it is vasoconstrictive, or constricts the capillaries in the nasal membranes, and reduces the surface area and makes absorption slow and incomplete. However, only 30 to 60 percent is actually absorbed. Also the larger the dose, the larger percentage of the drug is absorbed.

Snorting cocaine produces maximum physiological effects within 40 minutes and maximum psychotropic effects within 20 minutes. Effects are maintained approximately for an hour after peak effects are felt.


Cocaine, like other CNS stimulants such as amphetamine, caffeine, and nicotine, produce alertness and heightens energy. Cocaine acts on the CNS by inhibiting the re-uptake of the neurotransmitter norepinephrine. The augmentation of norepinephrine results in increased motor activity, with slight tremors and convulsions in the user’s extremities. In the cardiovascular system, the heart rate is increased; the blood pressure elevated, and other hypertension like symptoms are experienced. Because cocaine permits less body heat to escape, users generally experience an increase in body temperature. In overdose cases temperature have been recorded as high as 114F.


Cocaine also inhibits the reuptake of dopamine, a neurotransmitter that controls the pleasure centers in the CNS, causing a sense of euphoria, a decreased anxiety in social inhibitions, and heightened sexuality. Increased dosages of cocaine produce euphoria experiences that create vivid, long-term psychological memories that form the basis for subsequent craving of the drug. Hallucinations and psychoses have been reported with increased dosages of cocaine, including foraging and “skin-picking”(bugs crawling on skin sensation). Cocaine use also causes the user to crave other drugs, including alcohol. Drug dependence can be both psychological and physiological.


While cocaine is not physiologically addicting, users may experience anxiety and depression when a drug is not available. These sensations, while possibly affecting physical systems in the body have not been demonstrated to be related to bodily function. In other words, these sensations have been classified as psychological manifestations resulting from psychological dependence.


Psychological dependence is a compulsion for repeated use of a drug for its euphoric effects despite any adverse effects that might occur. Cocaine exhibits, powerful reinforcing properties that cause users compulsively to misuse the drug resulting in psychological addiction. The psychological craving for the drug is the most important contributor to its abuse potential. Users find that higher doses intensify the high. So unless the user has imposed a limit on the amount of drug used during a fixed period some users will gradually increase the frequency of use and quantity of the dose. The pursuit of the “higher high” becomes so great that some may often ignore all signs of physical and psychological risk. With continued use the false self confidence associated with the high diminishes and depression and irritability set in. In attempt to ward off the depression or “crash,” from the high, users binge for several hours or several days.

Drug tolerance is the process by which the effectiveness of a drug diminishes over time such that increasing doses are necessary to achieve effects comparable to prior doses. Acute tolerance is defined in as a change in responsiveness to a drugs effect in the short term, even within a single dose. Cocaine’s effects dissipate quickly but the drug continues to be present in the bloodstream, long after the effects are no longer felt. When tolerance occurs users need increasing amounts of the drug to achieve the same high. Experienced users are often able to take doses that would otherwise be fatal to a first time user.

Chronic cocaine use causes a decrease in the production of enkephlin, one of the brains natural opioids. This in turn causes a compensatory increase in the number of mu-receptors. The number of un-occupied mu-receptors may be associated with the craving and abstinence syndrome. After chronic exposure to cocaine the number of post-synaptic dopamine receptors in the CNS is reduced. The user in the absence of cocaine, his pre-synaptic neurons sequester dopamine in the synaptic cleft with greater efficiency. This is what induces depression, sometimes severe.

No one ever feels content after taking cocaine they just want more.




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