Stimulant

A stimulant is a drug that increases the activity of the sympathetic nervous system and produces a sense of euphoria or the feeling of being more awake. Stimulants can be used as recreational drugs or therapeutic drugs to increase alertness. They are also used and sometimes abused to boost endurance and productivity as well as to suppress appetite. Examples of stimulants are caffeine, amphetamines, ecstasy and cocaine.

Amphetamines are synthetic stimulants. They were first discovered in the 1800s, but their medical uses were not recognized until the 1930s. Then they were used to counter low blood pressure, help asthmatics breathe more easily and decrease appetite. However, taking a lot, especially over a few days, can produce panic and paranoia. Injecting amphetamine is particularly dangerous. If injecting equipment is shared, there is the risk of infection including hepatitis and HIV.

Cocaine is made from the leaves of the coca shrub, which grows in the mountain regions of South America in countries such as Bolivia, Colombia, and Peru. In Britain and America, the most common form of cocaine is as a white crystalline powder. Most users insufflate it up the nose, often through a rolled banknote or straw, but it is also sometimes made into a solution and injected. Crack is a smokeable form of cocaine. It is usually smoked in a pipe, glass tube, plastic bottle, or foil. Cocaine and crack are strong, but short-acting stimulant drugs. Crack in particular has strong but short-lived effects. Both drugs tend to make users feel more alert and energetic. Many users say that they feel very confident and physically strong. Common effects include dry mouth, sweating, loss of appetite, and increased heart and pulse rates. Excessive doses can cause death from respiratory failure or heart failure.

Caffeine is a drug that is found in tea, coffee, cocoa, many soft drinks, and some chocolates. There is no law prohibiting the sale of any of these products. Caffeine helps stimulate the body, increasing heart rate and blood pressure. It decreases tiredness and drowsiness, and makes people feel more alert and able to concentrate. Caffeine is a diuretic (a drug that increases urination). There have been concerns about the amount of caffeine consumed by young children particularly in soft drinks and chocolate. Some people have suggested that children that consume a lot of caffeine may become hyperactive.

MDMA is an illegally-manufactured drug that comes either in tablet or capsule form (known as ecstasy), as a powder (MDMA dibs or powder) or crystal (MDMA crystal in the US, Crystal in the EU). The consumption of a typical dose increases the blood pressure and heart rate, and loss of appetite is common. Users of MDMA experience brief nausea, rapid sweating, and a dry mouth and throat. The appearance of ecstasy tablets varies considerably, ranging from brown, white or pink tablets to yellow, clear, red-and-black or red-and-yellow capsules. Some also have pictures, designs or logos on. It is very unusual for an ecstasy pill to contain only MDMA; they frequently contain amounts of other drugs including MDA, MDEA, MDBD, PCP, DXM, PMA, Ketamine, Caffeine, Amphetamine, Methamphetamine, Ephedrine, Pseudoephedrine, Aspirin, Paracetamol, Fentanyl and, in a small number of cases, Heroin, Cocaine, Mescaline, DOB, or LSD. In some cases the substance sold as ecstasy pills need not contain MDMA at all. Contrary to popular belief amongst non-users MDMA does not cause hallucinations, however many of the other drugs which are included in Ecstasy pills are hallucinogens. Deaths that have occurred as a result of consumption of ecstasy have mainly been connected with non-stop dancing in hot, crowded clubs leading to overheating and dehydration, or to multiple-drug overdoses, hyponatraemia or water intoxication as in the case of Leah Betts. Safety advice when using MDMA includes taking a break from dancing to cool down, drinking moderate amounts of water (sufficient to replace that lost by sweating; the commonly given advice here is sip don't gulp) along with small amounts of salty foods or drinking sports drinks instead of water (to prevent hyponatraemia) and avoiding diuretics (caffeine, alcohol).

Antidepressants are not considered stimulants, as they do not act directly on the sympathetic nervous system and generally do not produce an immediate effect on mood. A possible exception is bupropion, whose chemical and pharmacological properties are similar to those of stimulants.

Attention deficit disorder is often treated using stimulant medications, the most popular of which include Ritalin (methylphenidate), Adderall (amphetamine), and Dexedrine (dextroamphetamine).

Recently, there have been improvements in the area of stimulant pharmacology, producing a class of chemicals known as eugregorics, or good arousal. These stimulants tend to increase alertness without the peripheral (body) effects or addiction/tolerance/abuse potential of the traditional stimulants. They have minimal effect on sleep structure, and do not cause rebound hypersomnolence or "come down" effects. Currently, there are two stimulants in this class being used: modafinil and adrafinil, marketed as Provigil and Olmifon, respectively.

Stimulans Stimulans Stimulant Estimulante Stimulant 覚醒剤