STIMULANTS

STIMULANTS. Foods and drinks (and other substances) that stimulate the consumer to enhanced mental alertness, increased or prolonged physical activity, uninhibited conviviality, or fierce fighting are called "stimulants." This definition is intentionally a narrow one. It excludes the great majority of nourishing foods, for example, because a nourishing meal in itself produces, alongside a feeling of well-being, somnolence (sleepiness) rather than alertness and activity. It also excludes substances such as cannabis and opium (both occasionally taken as foods) that depress mental and physical activity: these are sedatives, not stimulants. We must distinguish enhanced mental alertness from hallucination, the tendency to see what isn't there; hallucinogens are, therefore, also excluded. Other exclusions include appetizers, which stimulate the appetite for food, and aphrodisiacs, which (to the extent that such foods really exist) stimulate sexual appetites and energies.

Using foods that have a stimulant effect provides ways of intentionally adjusting the body's metabolism, which carries risks. There is a good reason why a nourishing meal produces sleepiness: after such a meal, the body is occupied with digestion. Postponing or interrupting that activity may produce digestive disturbance. In any case, increased alertness and physical activity will eventually be paid for in greater-than-usual exhaustion, and there may be other undesirable aftereffects. For example, it may be necessary to compensate for the aftereffects of stimulants by using them again. If the desired effect lessens after frequent use, increased quantities might be needed. In this way, regular use turns into dependence and addiction.

It is even more true of stimulants than of foods in general that their use is not independent of its social context, but no simple generalization is possible. Some of the foods discussed here are nearly always taken in company, as part of a social ritual. Some are nearly always taken as part of, or immediately before or after, a meal. Some, however, are customarily taken when one is not in company and not eating a meal; such habits may vary from one culture to another. External observers focusing on individual psychology may see the solitary use of stimulant foods as posing a personal, social, or criminal problem, while social use might be perceived as no problem or as a different kind of problem. Furthermore, observers focusing on social groups will find users of these stimulant foods to be unexpectedly protective, even nationalistic, about the preferred means of preparing them, which may vary widely.

Stimulant foods have been identified, like nearly all other foods and like many thousands of medicinal plants, in the course of very long-term unrecorded experiments: each human community explores its environment, notes animals and plants that may be of use, finds ways to use them, sometimes begins to farm them, and to trade in them. The stimulant effects of these foods were discovered empirically, as were their associated side-effects and dangers. In the last two centuries, chemists and nutrition scientists have identified their active constituents, making possible for the first time a scientific explanation of their effects.

In general, stimulant foods and drinks are either taken in a neutral vehicle, such as hot water, or they are slowly extracted by chewing. Nonfood stimulants are often taken as smoke or snuff. These various methods all ensure gradual absorption with relatively little interference from other foods. Alcoholic drinks are unusual because they are frequently taken without admixture and often contain strong flavorings: however, water is the principal constituent of most alcoholic drinks, and more water is often added.

Most traditional cultures had one, or at the most two, familiar stimulants. Globalization has changed this, producing such effects as the worldwide fashion for coffee; the worldwide marketing of chocolate, instant coffee, and the "cola" drinks; and the complex social interplay between alternative stimulants of almost equal status, neatly symbolized by the ritual question at breakfast in a French hotel, "Café? Thé? Chocolat?" (Coffee? Tea? Hot chocolate?)

Caffeine

Caffeine is among the commonest of stimulants worldwide. It is the chief active constituent in coffee and tea, which are familiar in practically every country, and in maté, guaraná, and cola nut, which are popular in South America and West Africa. It is present in smaller quantities in some other stimulant foods, including chocolate.

Coffee. Coffee consists of the roasted, ground beans of Coffea arabica. Native to Ethiopia, its use spread in late medieval times to Yemen; from there it rapidly became popular around the Mediterranean. Both Arabs and Europeans encouraged its further spread. Details of its use vary. Boiling water is added; commonly sugar is used as a flavoring, and sometimes milk or cream. Often coffee is drunk after meals, but it is also often taken between meals, both by groups as a social drink and by workers as a stimulant. Several substances have been used as coffee substitutes. Most of them had the advantages of being cheap and of tasting somewhat like coffee but the

disadvantage of containing little or no caffeine. These substitutes have now been overtaken in popularity by instant coffee, a soluble product manufactured from the beans of Coffea robusta, which does contain caffeine.

Tea. Tea is made from the dried leaves of Camellia sinensis, native to southern China. The use of tea was already spreading beyond China in the ninth century; like coffee, it became popular in Europe in the seventeenth century and its use then spread worldwide. Again, like coffee, details of its use vary. Boiling water is usually poured onto the leaves, which are then allowed to steep for a few minutes. The resulting liquid is much lighter in flavor and color than coffee. Some add sugar to it: fewer, notably the British, add milk; some drink it iced. Tea is more often taken between meals than during meals; like coffee, it is used both as a social drink and by workers as a stimulant.

Caffeine beverages in South America. Maté, also called Paraguayan tea, is made by pouring boiling water onto the dried and roasted leaves of yerba maté (Ilex paraguariensis ). Most of the leaves that are used come from wild trees gathered from the forests of southern South America. Maté is traditionally a social drink, made in a gourd or a silver pot and sucked through a shared straw or silver tube. It is drunk while still extremely hot, so added pleasure is provided by watching the reactions of unskillful foreigners who burn their lips and mouths while trying to drink it. It is usually taken without sugar, but sometimes orange zest is added as a flavoring. Maté is the national beverage of Argentina and Paraguay but has never spread beyond the region. The plant is a relative of European holly (Ilex aquifolium ), whose leaves have occasionally been used to make a narcotic drink; more importantly, it is related to yaupon or Carolina tea (Ilex vomitoria ) and other species that have been used to make stimulating and narcotic drinks by North Americans both before and after European settlement.

Guaraná (Paullinia cupana ) is a tropical plant native to Brazil. Its seeds are traditionally roasted, pounded, and made into cakes called "Brazilian chocolate." They have this name not because they can be eaten solid, like modern chocolate bars, but because in pre-Columbian Mexico travelers used to carry similar cakes of powdered cacao for use in making an instant chocolate drink. Like those, cakes of guaraná are traditionally crumbled into water by tired travelers in Brazil, making a stimulating drink particularly rich in caffeine. Guaraná is now also used as a flavoring for soda, candy, and liqueurs.

Caffeine in Africa. The cola nut, a rich source of caffeine, is the usual native stimulant of West and Central Africa. It might rather be called a seed, since eight or ten of them are found in each fruit of the trees Cola nitida and C. acuminata. These seeds are white, pink, or red: the white ones are said to be the best. They are customarily chewed before meals: they have a bitter flavor but, perhaps as a result of this, foods and drinks taken afterwards seem sweet (water, taken after cola, tastes "like white wine and sugar," according to one observer). Apart from this effect as an appetizer, cola nuts have a high reputation among their traditional users, as stimulant, digestive, and aphrodisiac. Alongside caffeine, they contain theobromine (as does chocolate) and kolanin, a heart stimulant. Cola nuts can also be ground into powder and mixed with water as a drink, and cola extract is used to flavor sodas and candies: the names of Coca-Cola and Pepsi-Cola allude to cola nuts, which may well be an ingredient in these products.

Theobromine

Theobromine is the chief active ingredient in cacao beans, the seeds of the tropical tree Theobroma cacao. These beans, fermented, roasted, and ground, are the raw material for chocolate, the traditional stimulant of Mexico, familiar worldwide. In pre-Columbian civilizations, chocolate was used as a drink: the ground cacao was mixed into hot water, which was then poured from a height into the serving cup to produce the much-desired foam. Flavors (chili, vanilla, or others) and color (notably annatto) might be added. Popularized in Europe by the Spanish, chocolate became successively a sugary drink and a milky drink; many other flavorings were tried, including the cinnamon now favored in Mexico. Eventually (in the nineteenth century) chocolate was made into bars to be eaten solid, and in many countries this is now its most familiar form. In the Maya and Aztec civilizations, chocolate was a social drink, taken after dinner, serving as a stimulant (and, according to some, an aphrodisiac). Whole chocolate contains caffeine as well as theobromine, and it is also rich in cocoa butter, making it an extremely nourishing food and, therefore, unlikely to produce aftereffects such as exhaustion.

Nicotine

Tobacco, the fermented leaf of Nicotiana tabacum, is usually smoked; in that form it cannot be classified as a food. It can be chewed, however. In Western cultures, chewed tobacco has been typical of sailors and other manual workers subjected to extreme weather conditions that make smoking difficult. Tobacco's active ingredient, nicotine, a deadly poison in the pure state, acts as a stimulant when slowly absorbed.

In Australia, another plant, Duboisia hopwoodii, has leaves and flowers very rich in nicotine. Aborigines dry and grind the leaves, mix them with the ash of certain other plants, and roll them into balls, called "pituri," for chewing. These are used by solitary workers and travelers as a stimulant to stave off tiredness and hunger; they are also exchanged as a sign of friendship. They are, or were, used by warrior groups in preparation for a battle. There is a definite advantage in chewing ash in pituri (and also with coca and betel nut), because alkalis in the ash detach the active stimulant substance, in this case nicotine, from the plant acids, allowing it to be more rapidly absorbed. The use of ash in this way has developed, apparently independently, in Australia, southeastern Asia, and South America.

Cocaine

Coca is the dried leaf of a plant species native to western South America, Erythroxylum coca, and of a second species, E. novogranatense, which developed under cultivation. Coca leaves were known as a stimulant to the pre-Columbian peoples of the Andean region, and continued to be used by them and their Spanish conquerors. Their use is extremely widespread in South America. As with the nicotine plants, the principal use of coca leaves has been as a stimulant for workers and travelers. The usual way is to take some leaves, mix them with the ash of burnt coca or another wood, roll the mixture into a ball, and chew it. Coca leaves, like chocolate, are really nourishing, a property that tends to reduce the severity of the exhaustion that usually follows the use of stimulants. The active constituent of coca leaves was isolated (and named cocaine) in 1860. When taken in the pure form, cocaine was found to be a useful medicinal drug but also highly addictive. It was among the first stimulants to arouse strong medical and governmental disapproval. In the early twentieth century, many countries made it illegal. The name of Coca-Cola alludes to coca, and the early recipe for the product contained cocaine, like other soft drinks of the period.

Some other species of genus Erythroxylum contain cocaine or similar compounds and are used as stimulants by various South American peoples: E. cataractum by the Cubeo of Colombia; E. fimbriatum and E. macrophyllum by the Bora and Huitoto of Peru.

Other Stimulants

Betel. The commonest traditional stimulant of southern and southeastern Asia is betel. Like pituri and coca, betel is customarily made up as a chewing packet that includes ash. The active ingredient, arecoline, is contained in the areca nut or betel nut (the nut of the palm Areca catechu ), which is cut into long narrow pieces and placed inside the packet along with a "lime" made from burnt coral and oyster shells. The packet is formed from a leaf of the betel pepper vine (Piper betle ). In traditional households, the betel chews are made up each day from fresh supplies; as with pituri, it is a sign of friendship and hospitality to offer a chew to any visitor. The habitual chewing of betel eventually stains the mouth red and the teeth black. When it is first tried, betel can produce feelings of anxiety, excitement, and vertigo; to those who use it regularly, it is a mild stimulant.

Khat. Coffee, when it was introduced to Yemen from across the Red Sea, was not the country's first stimulant. That position belongs to khat (or qat), the leaf of Catha edulis. Khat is used in Yemen, Saudi Arabia, and a large area of East Africa from Ethiopia and Somalia to Mozambique and South Africa. It had not spread outside the region until some Americans acquired the taste for it while they were in Somalia with United Nations troops during the early 1990s. Khat is often taken as a tea, made by pouring boiling water onto the dried or fresh leaves. Fresh leaves can also be chewed; in this form its effect is said to be stronger than coffee but not as strong as alcohol. When chewed, khat is often used socially because it enlivens conversation. The principal active constituent in khat is cathinone, now classified as an illegal drug in the United States; however, cathinone is only present in fresh leaves. The second active constituent, cathine, which is still present in the dried leaves, is an appetite suppressant.

A milder stimulant of the same general type is Mormon tea, the leaf of Ephedra nevadensis. These leaves contain the active ingredient pseudoephedrine, and are made into a tea with boiling water.

Kava. The root of the plant kava-kava, Piper methysticum, is the source of kava, a familiar stimulant used in Hawaii and other Pacific islands. The fresh root is chopped or ground and then soaked and squeezed in water to produce a milky, spicy liquid, which is traditionally served in half coconut shells. Kava is a social drink whose effect is to produce a condition physically resembling drunkenness, though with apparent clarity of mind. The principal active constituents are known as kavalactones.

Kratom. Kratom, a stimulant indigenous to Thailand and little known elsewhere, consists of the leaves of Mitragyna speciosa. These leaves can be smoked or made into a tea. The active constituent is mitragynine, which, like cocaine, is a stimulant at low doses but a narcotic at higher doses.

Alcohol

Alcohol is an atypical stimulant because it is not naturally present in any fresh plant. It is produced from the fermentation by yeast of plant sugars. One starting point is a fruit juice. Grape juice makes wine; apple juice makes (hard) cider; pear juice makes perry. Several other fruits are used in various parts of the world. A second starting point is malted cereal: barley is the commonest choice, and the result is beer. Plant saps can be used if they contain sufficient sugar: liquid cane sugar is so used in India, while pulque, a Mexican alcoholic drink, is made from the sap of the maguey (Agave atrovirens ). Finally, honey, mixed with water, can be used, and the result is mead (a beverage that figures importantly in the Old English epic Beowulf ). There are two common adjustments to the process: adding cane or beet sugar to the original juice gives the yeast more raw material to work with, producing more alcohol; distilling the final product achieves much greater concentrations of alcohol, resulting in "hard liquor."

Wine and beer are both ancient inventions, going back to southwestern Asia several thousand years b.c.e. But yeasts are naturally present in the air; therefore, alcoholic drinks might have been invented or discovered many times in human history; certainly, the origin of pulque is independent of those of wine and beer.

Alcoholic drinks have most generally, in traditional societies, been used as social drinks, and they have commonly been used in a ritualistic way as well. Their production is linked with the seasons (in general the required juices are available only when fruit is ripe, and the fermentation process takes time); therefore, by contrast with most other stimulants, the discovery of alcoholic drinks and the annual vintage (especially of wine) tend to be celebrated in major festivals. In many cultures, the ordinary, everyday consumption of alcohol follows precise rules, tending to ensure, for example, that everyone drinks equally. Both in the major festivals and in everyday social drinking, it is commonly the case that drunkenness is aimed at, at least to the extent of the loss of inhibitions, but sometimes going all the way to unconsciousness.

Like kava—and unlike many stimulants—alcohol tends to produce enhanced mental activity accompanied by physical incapacity. In traditional societies, travelers used coca, maté, guaraná, pituri, and other stimulants to keep them going; they would not use alcohol or kava till they had arrived. Likewise, coffee, tea, and some similar stimulants may enhance one's ability to drive safely, for a certain period, while kava and alcohol impair it.

See also Alcohol ; Chocolate ; Cocktails ; Coffee ; Mexico and Central America, Pre-Columbian ; Spirits ; Tea .

BIBLIOGRAPHY

Bibra, Ernst von. Plant Intoxicants. Edited by Jonathan Ott. Rochester, Vt.: Healing Arts, 1995. Originally published as Der Narkotsischen Genussmittel und der Mensch. Nürnberg, Germany: Wilhelm Schmid, 1855. The 1995 edition is a major revision and expansion of Baron von Bibra's work, with an up-to-date bibliography that should be the starting point for further study.

Coe, Sophie D., and Michael D. Coe. The True History of Chocolate. London and New York: Thames and Hudson, 1996.

Henman, A. R. "Guaraná (Paullinia cupana var. sorbilis ): Ecological and Social Perspectives on an Economic Plant of the Central Amazon Basin." Journal of Ethnopharmacology 6 (1982): 311–338.

Kennedy, J. G. The Flower of Paradise: The Institutionalized Use of the Drug Qat in North Yemen. Dordrecht, Netherlands: Reidel, 1987.

Lebot, Vincent, Mark Merlin, Lamont Lindstrom. Kava: The Pacific Drug. New Haven, Conn.: Yale University Press, 1992. Reprinted as Kava: The Pacific Elixir. Rochester, Vt.: Healing Arts Press, 1997.

Lewin, Louis. Phantastica: Narcotic and Stimulating Drugs, Their Use and Abuse. Translated by P. H. A. Wirth. New York: Dutton, 1964. Originally published as Die Pfeilgifte; nach eigenen toxikologischen und ethnologischen Untersuchungen. Leipzig: J. A. Barth, 1923.

Plowman, Timothy. "The Origin, Evolution, and Diffusion of Coca, Erythroxylum spp., in South and Central America." In Pre-Columbian Plant Migration, edited by Doris Stone, pp. 125–163. Cambridge, Mass.: Peabody Museum, 1984.

Watson, P. L. The Precious Foliage: A Study of the Aboriginal Psycho-Active Drug Pituri. Sydney, New South Wales, Australia: University of Sydney Press, 1983.

Andrew Dalby

Stimulant drugs

Also called psychostimulants, drugs that produce increased levels of mental and physical energy and alertness and an elevated mood by stimulating the central nervous system.

Stimulants are used for the treatment of certain psychiatric conditions and also used (and abused) for recreational purposes, enhanced levels of energy, and weight loss. They may be prescription or over-the-counter medications, illegal street drugs, or ingredients in commonly ingested substances, such as the caffeine in coffee or the nicotine in cigarettes. Whatever their form, stimulants increase respiration, heart rate, and blood pressure, and their abuse can cause adverse physical effects and endanger a person's health and even his or her life. An overdose of stimulants can result in chest pains, convulsions, paralysis, coma , and death.

Caffeine and nicotine

The most commonly used stimulant (and the most widely consumed drug) in the United States is caffeine. Found in coffee, tea, soft drinks, chocolate, and drugs, including pain relievers, diet pills, and cold and allergy medications, caffeine belongs to a family of drugs called methylxanthines. It works by disrupting the action of a neurotransmitter called adenosine. Since caffeine is usually consumed in food, it normally enters the body through the gastrointestinal system, passing from the intestines into the blood, which circulates it through the body. It reaches its maximum effect within 30-60 seconds from the time it is consumed, although it remains in the body for several hours. Caffeine is addictive. People who consume it regularly develop a tolerance for it, meaning that they need to ingest progressively greater amounts to continue getting the same effect. (Thus, diet pills containing caffeine lose their effectiveness after a few days, when a tolerance is established.) Caffeine causes physical dependence, producing withdrawal symptoms including anxiety, headaches, and fatigue when its use is discontinued. People who stop using caffeine also experience a craving for it, which is a sign of psychological dependence. It is generally agreed that daily caffeine consumption equal to the amount contained in one cup of coffee or soft drink (under 240 milligrams) is probably harmless, but that consumption over 600 milligrams (the amount in four cups of coffee) can cause anxiety, sleep and digestive disorders, a rapid heartbeat, and other health problems. The National College Athletic Association has limited the amount of caffeine that its players can consume.

Besides caffeine, the other stimulant widely ingested is the nicotine consumed in smoking. Both caffeine and nicotine are classified as secondary stimulants because, unlike drugs such as amphetamines and cocaine, they affect the sympathetic nervous system more than the central nervous system . Also unlike stimulants that are abused for recreational purposes, caffeine and nicotine produce only an increased energy level but not a feeling of intoxication. Nicotine acts mostly as a stimulant in new users, but long-term users claim that it relaxes them. Teenage smoking has been rising steadily throughout the 1990s. A 1995 survey of high school students by the Centers for Disease Control and Prevention found that on average 34.8% of teenagers smoke. Like users of other addictive substances, teen smokers start out thinking they will be able to control their use of cigarettes, but two-thirds of young people who smoke have tried to quit and failed. Nicotine withdrawal symptoms include anxiety, irritability, insomnia, depression , headaches, mood swings, difficulty concentrating, and changes in appetite.

Stimulants used for therapeutic purposes

Stimulant drugs have long been used to treat psychological disorders. In the past, psychiatrists used certain stimulants as antidepressants , but today this practice is confined primarily to seriously depressed patients who have failed to respond to either psychotherapy or to the wide range of other antidepressants that are currently available (and that, unlike stimulants, are not addictive). Today the primary therapeutic use of stimulants is for the treatment of attention deficit/hyperactivity disorder (ADHD) in children, and the most widely used drug is Ritalin (methylphenidate). Ritalin works by facilitating the release of the neurotransmitter norepinephrine, which improves alertness, attention span, and the ability to focus. Although it is generally considered safe and effective for the treatment of ADHD, there is still controversy surrounding the frequency with which this medication—whose use by children doubled between 1988 and 1994—is prescribed. Side effects include insomnia, appetite loss, and stomach pains. Ritalin may also produce withdrawal symptoms, including headache, irritability, nausea, and abnormal chewing movements and movements of the tongue. Other stimulants used for ADHD (usually when Ritalin doesn't work or produces too many negative side effects) are Dexedrine and Cyclert (pemoline), a stimulant similar to Ritalin. Ritalin and other stimulants have also been prescribed to prevent daytime sleep episodes in persons suffering from severe narcolepsy .

Abuse of illegal stimulants

The primary illegal stimulants used for recreational purposes are amphetamines and cocaine. Street names for various types of amphetamines include speed, uppers, dexies, bennies, ice, L.A. ice, Ecstasy, and crank. Amphetamines produce an effect similar to that of the hormone adrenaline, making its users feel awake, alert, and energetic. Drugs of this type were abused by young people as early as the 1930s, when it was popular to tear the medicated strip out of Benzedrine nasal inhalers and ingest them directly or in coffee. By the 1950s and 1960s amphetamines were widely used by people who needed to keep themselves awake through the night, such as truck drivers and night musicians, or by athletes for extra energy. Many young people used them to stay awake when they needed to cram for tests or complete school assignments. It is estimated that up to half the amphetamines sold by drug companies in the 1960s were sold illegally. After the government imposed controls on the manufacture of these drugs, they began to be produced illegally in home laboratories. Not only are these preparations vulnerable to contamination, they are often diluted by manufacturers and dealers. Many supposed amphetamines sold on the street contain mostly caffeine and other drugs, with a very small percentage of amphetamine or even none at all.

The use of amphetamines declined in the 1980s as cocaine became the drug of choice. However, in the 1990s methamphetamine (traditionally known as speed) has become newly popular, especially among middle-class suburban teenagers, in a crystalline form—known as ice, L.A. ice, or crank—that can either be smoked or snorted like cocaine. Smoking methamphetamine first became fashionable in Hawaii. Use of the drug then became widespread in California, and now it is increasing in other parts of the country. A 1994 survey conducted at the University of Michigan found that more high school seniors had used methamphetamine than cocaine. In 1993 alone, the number of emergency room admissions related to the use of this drug increased by 61%. Crank is much cheaper to produce than cocaine, so its manufacturers realize a larger profit (a pound can be produced for $700 and sold for as much as $225,000). Users like it because it reaches the brain almost immediately, and its effects last longer than those of cocaine. It produces feelings of alertness, euphoria, and increased energy. Like other amphetamines, crank also decreases appetite and promotes weight loss, making it attractive to young women, who represent 50% of the teenage market for the drug.

People taking methamphetamine, which remains in the body for as long as four days, quickly establish a tolerance for the drug and require ever greater amounts to experience the same effect. Users can become addicted within four to six months. Side effects of the drug include a dry mouth, sweating, diarrhea, insomnia, anxiety, and blurred vision . Severe reactions can include hallucinations (called "tweaking"), paranoia , and speech disorders, all of which may persist for up to two days after use of the drug. In addition to physical addiction, amphetamines produce a psychological dependency on the euphoric effects produced by these drugs, especially since when they wear off they are followed by a "crash" that produces a depression so severe it can lead to suicide.

A related stimulant, which is derived from methamphetamine, is MDMA, also known as Ecstasy. MDMA combines the characteristics of a stimulant and a psychedelic drug, producing hallucinations and enhanced feelings of sociability and closeness to others. It is less addictive than amphetamines but more dangerous. Persons have died from taking this drug; some had preexisting heart conditions, but others had no known medical problems. MDMA causes brain damage, and its use can lead to the development of panic disorder.

Cocaine is a stimulant made from the leaves of the coca plant. Its street names include coke, snow, toot, blow, stardust, nose candy, and flake. When the pure drug was first extracted from the leaves in the 19th century, its harmful effects—including addiction—weren't known, and early in the 20th century it was legally sold in medicines and soft drinks, including Coca-Cola, which originally contained small amounts of the substance (from which its name is derived). Cocaine use has been illegal since 1914. Until the 1970s it was not widely used, except among some members of the arts community. At first cocaine was largely used in a diluted powder form that was inhaled. Eventually, more potent smokable forms were developed, first "freebase" then "crack," which has been widely used since the 1980s. In 1988, the National Household Survey on Drug Abuse reported that 1 in 10 Americans had used cocaine. Of young adults between the ages of 18 and 25, one in four reported having used cocaine at some point. Cocaine also became visible as a substance abused by celebrities, including actor John Belushi (who died of a cocaine-heroin overdose), comedian Richard Pryor (who was badly burned freebasing cocaine), and Washington, D.C. mayor Marion Barry, who was forced to resign from office but was later reelected. In 1991, a government study found that 15% of high school seniors and 21% of college students had tried cocaine, and cocaine use by teenagers continued to increase significantly through the 1990s.

Cocaine produces a physical addiction by affecting the brain's chemistry and a psychological addiction because users become dependent on the confident, euphoric feeling it creates to help them cope with the stresses of daily life. Possible negative reactions to large doses of cocaine use include hallucinations, paranoia, aggressive behavior, and even psychotic "breaks" with reality. Cocaine can cause heart problems, seizures, strokes, and comas. Reactions to withdrawal from the drug are so severe that most users are unable to quit without professional help. Withdrawal symptoms, which may last for weeks, include muscle pains and spasms, shaking, fatigue, and reduced mental function. Both inpatient and outpatient programs are available to treat persons for cocaine addiction.

Further Reading

Carroll, Marilyn. Cocaine and Crack. The Drug Library. Springfield, NJ: Enslow Publishers, 1994.

Chomet, Julian. Speed and Amphetamines. New York: Franklin Watts, 1990.

DeBenedette, Valerie. Caffeine. The Drug Library. Springfield, NJ: Enslow Publishers, 1996.

Jahanson, C.E. Cocaine: A New Epidemic. New York: Main Line Book Co., 1992.

Lukas, Scott E. Amphetamines: Danger in the Fast Lane. New York: Chelsea House, 1985.

Salzman, Bernard. The Handbook of Psychiatric Drugs. New York: Henry Holt, 1996.

Further Information

Drug Abuse Clearinghouse. P.O. Box 2345, Rockville, MD 20847–2345, (301) 443–6500, (800) 729–6686.

National Cocaine Hotline. (800) COCAINE.

Stimulant drugs

Definition

Stimulant drugs are drugs that excite the central nervous system.

Description

There are several drugs used as stimulants. Although in large part they share the same properties, their use is determined by how well they are absorbed from the gastrointestinal tract. These drugs are related to the body's normal stimulant hormones epinephrine and norepinephrine.

• Injectable stimulants are used to stimulate the heart or breathing. Epinephrine (adrenalin) is the most common.
• Topical stimulants are used as decongestants , since they cause blood vessels to contract. They are also used to stop superficial bleeding by contracting the capillaries and for relief of conjunctivitis . They may be applied to the skin, inhaled, or applied in the form of drops as nose drops or eye drops.
• Oral stimulants, including the two drugs in this class (methylphenidate [Ritalin] and amphetamine) are used to treat extreme daytime sleepiness also known as narcolepsy and for their calming effect in attention-deficit hyperactivity disorder (ADHD).
• Caffeine, a stimulant found in foods and drinks, is used to promote wakefulness and alertness.

The orally active stimulants were formerly used as an aid to dieting but were of little value for this purpose. They may still be used in the most extreme cases of obesity but are no longer routinely prescribed for this purpose. Some were widely used as decongestants for colds and allergies . They are subject to abuse, and amphetamines and methylphenidate are controlled substances in the United States.

Pemoline (Cylert) is also a member of this class but is rarely used because of its potential for causing severe liver problems. This drug should be reserved for treatment of children whose ADHD cannot be controlled with either first or second line drug therapy and whose condition is so severe that the potential benefits justify the risk.

Stimulant drugs, in addition to their proper medicinal use, are subject to abuse. The drugs commonly abused are methylphenidate, amphetamine, and methamphetamine. A related drug, 3,4-methylenedioxymethamphetamine (better known as ecstasy or MDMA), is also widely abused. Unlike methylphenidate and amphetamine, MDMA has no legitimate therapeutic use.

Cocaine is chemically different from the traditional stimulants but provides similar effects. It is used medicinally as a local anesthetic but is not available for self-administration. Cocaine has become a major drug abuse problem.

General use

The most common use of methylphenidate and amphetamine in children is for control of attention-deficit/hyperactivity disorder . This is a condition marked by general restlessness, excessive activity, and inability to concentrate on a topic. Children who have this problem are unable to concentrate on schoolwork and fall behind their classmates. They are frequently disruptive. For this condition, the stimulants have a reverse activity and have a calming, rather than a stimulating effect.

Precautions

Stimulant drugs are subject to abuse and development of tolerance. This does not appear to be a problem, however, when the drugs are appropriately used for a proper diagnosis of ADHD.

When used to treat young children, there is some evidence that stimulant drugs reduce the rate of growth. This may be made up for by a growth spurt when the drugs are discontinued.

Stimulant drugs increase blood pressure.

Side effects

The side effects for stimulant drugs are different when they are used as stimulants and when they are used for their calming effect in ADHD. The effects listed below are those seen when amphetamines and/or methylphenidate are used to treat attention-deficit hyperactivity disorder:

• reduction in rate of growth
• exacerbation of related problems such as Tourette's disorder
• appetite suppression

There are many additional side effects seen when amphetamines or methylphenidate are used or abused for their stimulant properties, but these effects are not normally seen when the stimulants are used for a proper diagnosis of ADHD and dosed appropriately.

Some of the adverse effects that may result from stimulant abuse are increased wakefulness, increased physical activity, decreased appetite, increased respiration, high fever , euphoria, irritability, insomnia, confusion, tremors, convulsions, anxiety , paranoia, and aggressiveness. The high fever and convulsions may be fatal. Long term abuse of stimulants may result in permanent brain damage that causes involuntary, Parkinson-like movements.

Methamphetamine causes increased heart rate and blood pressure and can cause irreversible damage to blood vessels in the brain, producing strokes. Other effects of methamphetamine include respiratory problems, irregular heartbeat, and extreme anorexia. Its use can result in cardiovascular collapse and death.

The reports of growth suppression associated with amphetamines and methylphenidate are not definitive but appear to be valid. This growth suppression is balanced by a growth spurt when the drugs are discontinued. For this reason, stimulants should only be administered during school hours and discontinued during summer and holiday periods.

Interactions

Stimulant drugs have no interactions with drugs that are normally prescribed for children.

Parental concerns

When used to treat ADHD, methylphenidate and amphetamines do not have the adverse effects associated with these drugs when they are abused.

ADHD is a difficult diagnosis and may be confused with normal childhood energy. A diagnosis should be made, and drug therapy initiated, only by a qualified professional experienced in this condition.

Because of the potential for abuse, methylphenidate and amphetamines must be kept out of reach of children, particularly visitors and older siblings of a child being treated for ADHD.

Because of the risk of growth suppression, stimulant drugs should only be administered during school periods. They should not be used to calm an active child for the convenience of parents or babysitters.

Children who fail a trial of one stimulant may respond to another drug in the same class. A child who does poorly on methylphenidate may respond to amphetamines and vice versa.

Approximately 15 to 30 percent of children with ADHD have underlying Tourette's disorder, a condition marked by vocal and motor tics . Starting treatment with methylphenidate or amphetamines may unmask the condition, and the tics will become apparent. This is not an effect of the drug, but rather a consideration of the underlying problem.

There is some dispute over the lowest age at which stimulant therapy may be appropriately started, but it seems agreed that these drugs should not be used to treat children under the age of three years.

Sometimes, drugs which are properly prescribed for ADHD are diverted and used by other children as recreational drugs. If a child who has been well stabilized on stimulants for ADHD begins to get worse, consider the possibility that the drugs are being sold to others, rather than being used therapeutically. Stimulant drugs should be administered by a parent, guardian, school nurse, or other responsible person. This will both guard against diversion and assure that children are not forgetting to take their medication.

The effects of cocaine are generally similar to those of amphetamines.

Signs of possible stimulant abuse, regarding amphetamines and cocaine, include dilated pupils, frequent lip licking and dry mouth, excessive activity, and lack of sleep . The drug abuser becomes talkative, but the discussion lacks continuity or coherence, and the subject changes frequently.

See also Caffeine.

Resources

BOOKS

Beers, Mark H., and Robert Berkow, eds. The Merck Manual, 2nd home ed. West Point, PA: Merck & Co., 2004.

Breggin, Peter. The Ritalin Fact Book: What Your Doctor Won't Tell You. New York: Rosen Publishing Group, 2003.

Ferreiro, Carmen. Ritalin and Other Methylphenidate-Containing Drugs. Langhorne, PA: Chelsea House, 2004.

Mcevoy, Gerald, et al. AHFS Drug Information 2004. Bethesda, MD: American Society of Healthsystems Pharmacists, 2004.

Mercogliano, Chris. Teaching the Restless: One School's No-Ritalin Approach to Helping Children Learn and Succeed. Boston, MA: Beacon Press, 2004.

PERIODICALS

Charach, A., et al. "Stimulant treatment over five years: adherence, effectiveness, and adverse effects." Journal of the American Academy of Child and Adolescent Psychiatry 43 (May 2004): 559–67.

Spencer, T. J. "ADHD treatment across the life cycle." Journal of Clinical Psychiatry 65 Suppl. (2004): 22–6.

WEB SITES

"Amphetamines (Systemic)." MedlinePlus. Available online at <www.nlm.nih.gov/medlineplus/druginfo/uspdi/202031.html> (accessed January 17, 2005).

Samuel Uretsky, PharmD

KEY TERMS

Attention deficit hyperactivity disorder (ADHD) —A condition in which a person (usually a child) has an unusually high activity level and a short attention span. People with the disorder may act impulsively and may have learning and behavioral problems.

Tic —A brief and intermittent involuntary movement or sound.

Tourette syndrome —A neurological disorder characterized by multiple involuntary movements and uncontrollable vocalizations called tics that come and go over years, usually beginning in childhood and becoming chronic. Sometimes the tics include inappropriate or obscene language (coprolalia).

Stimulants

The substances referred to as stimulants are a variety of compounds that excite the central nervous system or alter the body's metabolic activity. Some stimulants enhance alertness and increase energy whereas others affect emotions and oppose psychological depression.

One way in which chemical stimulants function is to mimic or enhance the effects of hormones that prepare animals for "fight or flight" when they are faced with threatening situations. They bring about an increased heartrate, increased blood pressure, and an increased rate of respiration. One way in which such hormones (or their imitators) prepare the body for sudden action is to increase the breakdown of glycogen and glucose in order to meet the increased demand for energy. The best examples of these hormones are the catecholamines (epinephrine, also known as adrenalin , and norepinephrine, also known as noradrenalin). The hormones bind to receptors on target muscle cell membranes and prompt formation of cyclic adenosine monophosphate (cAMP), known as a "second messenger" because it transmits a signal to many intracellular molecules involved in metabolism (epinephrine and norepinephrine being first messengers). In order for a subsequent message to be received (and for intracellular alterations related to fight or flight to be maintained), hormones and second messengers must be rapidly removed from cell surfaces once they have delivered their messages. An enzyme classified as a phosphodiesterase degrades cAMP to a form that is inactive. Some of the most common stimulants, such as caffeine and related compounds in tea and chocolate, inhibit the phosphodiesterase enzyme so that cAMP levels remain high enough to maintain the alerted state.

A second way in which stimulants exert their effects is by inhibiting the neurochemistry that involves the transmission of signals from one nerve cell to another. When a nerve cell receives a signal, that signal is propagated to the far end of the long nerve cell. In order for that signal to be transmitted to the next nerve cell, molecules called neurotransmitters are released into the spaces (synapses) between the cells. The neurotransmitters bind to specific receptors on the receiving cell, thus passing on the signal. In order to prepare for a new signal, neurotransmitters must be removed from the intercellular space through reuptake or degradation.

Cells can also recover from the signal for the fight or flight reaction by taking hormones that they have released back up into themselves. Cocaine interferes with the reuptake of adrenalin by cells in the cortex of the brain, thus intensifying the effects of adrenalin and producing a sense of euphoria and (sometimes) hallucinations. Cocaine use leads to psychological dependency and can cause convulsions, respiratory failure, and death.

Amphetamines are drugs that mimic the effects of epinephrine, or adrenalin. Because effects such as mental illness and brain damage can result from overuse of amphetamines, they currently have limited medical use. Metamphetamines are similar to amphetamines in structure and action but have fewer undesirable side effects. Ritalin (methylphenidate), commonly used to treat attention deficit disorder, has essentially the same mode of action as amphetamines. Ritalin abuse by middle and high school students has become a common concern.

Because of their adverse effects, the Food and Drug Administration (FDA) has taken action to remove two over-the-counter products that have amphetamine-like action: ephedrine, an agent with actions similar to those of epinephrine and the main active ingredient in the herb ephedra, used for weight loss and in energy-enhancement cold medicines; and weight loss products that contain phenylpropanolamine, which can raise blood pressure and increase the risk of stroke.

Opiates such as morphine and codeine are thought to enhance the release by neurons of the neurotransmitter dopamine; the release of dopamine leads to a sense of euphoria. These drugs are addictive and are often abused. In general, all antipsychotic medications work by blocking dopamine receptors in the forebrain. Nicotine mimics the action of the neurotransmitter acetylcholine at receptors having to do with the transmission of signals between autonomic nerve cells and skeletal muscle.

see also Caffeine; Epinephrine; Methylphenidate; Neurochemistry; Neurotransmitters; Norepinephrine.

Sharron W. Smith

Bibliography

Hardman, Joel G., and Limbird, Lee E., eds. (1996). Goodman & Gilman's The Pharmacological Basis of Therapeutics, 9th edition. New York: McGraw-Hill, Health Professions Division.

Voet, Donald, and Voet, Judith G. (1995). Biochemistry, 2nd edition. New York: Wiley.

stimulants A stimulant is a rather imprecise term used for a variety of different kinds of drug, some with medical uses and others with only recreational use. Psychomotor stimulants produce locomotor activity (the subject becomes hyperactive), euphoria, (often expressed by excessive talking and garrulous behaviour), and anorexia. The amphetamines are the best known drugs in this category, the actions in the central nervous system depending on the release of noradrenaline, dopamine, and possibly 5HT. Many tests show that the amphetamines reduce physical and mental fatigue, but the accuracy of mental deliberations is likely to be reduced also. Nevertheless, the amphetamines once enjoyed a reputation among students for improving performance at examinations. Excessive use leads to insomnia and repeated use leads to a level of dependence. Amphetamines also have actions outside the nervous system, causing hypertension.

cocaine is also a psychomotor stimulant and users are typically extroverted, party-loving individuals. Cocaine blocks the re-uptake of noradrenaline at synapses within the brain and elsewhere, with effects similar to the amphetamines. Cocaine is produced by bushy plants growing in Bolivia and Peru, and hardworking peasants chew the leaves to reduce the fatigue they feel from their toiling, but also to reduce hunger. The dependence which develops with cocaine presents a serious problem in the developed world.

caffeine and theophylline, both methylxanthines, found in tea, coffee, and some soft drinks, are mild psychomotor stimulants. They reduce mental and physical fatigue, without affecting locomotor activity or producing euphoria. It is doubtful whether caffeine and theophylline can produce true dependence. Methylxanthines have some other actions, causing increased urine production and stimulation of heart muscle.

Drugs of another type are used as respiratory stimulants in deeply comatose patients or those with respiratory failure. These are more properly described as analeptics (meaning restorative); nikethamide is an example. Some purgatives, such as cascara and senna, are described as stimulant purgatives and work in the gut, releasing substances which cause peristaltic movements and lead to a temporary diarrhoea.

Alan W. Cuthbert