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

Drugs used as appetite suppressors, weight reducers, and mood enhancers. They have also been misused in sport, particularly in endurance activities, to increase mental alertness, to conceal feelings of exhaustion, and to increase aggressiveness.

Exercisers using stimulants may force their body beyond safe limits. Several sudden deaths have been attributed to stimulants such as amphetamines and cocaine. All stimulants have the potential to increase heart rate and blood pressure with lethal results. In addition, even moderate stimulant use may result in loss of judgement and increase the risk of injury to both the user and others. Stimulants are banned by most sports federations, including the International Olympic Committee.

A pharmacological class of agents that boost mental alertness and physical activity by increasing heart and breathing rates, and brain functions. They act on the central nervous system to stimulate the body both mentally and physically. They have been used as appetite-suppressants and weight-reducing drugs, and to obtain a feeling of well-being. They have been misused in sport, particularly in endurance events, to increase mental alertness, to conceal feelings of exhaustion, and to increase aggressiveness. Athletes using stimulants may force the body beyond safe limits. Several deaths have been associated with the use of stimulants such as amphetamines. In addition, use of stimulants may result in loss of judgement and increase the risk of injury to both the user and others taking part in sport. Many stimulants are on the World Anti-Doping Agency's 2005 Prohibited List. These include amphetamine, cocaine, methamphetamine, and strychnine. However, although formerly on the International Olympic Committee's list of banned substances, bupropion, caffeine, phenylephrine, phenylpropanolamine, pipradol, pseudoephedrine, and synephrine are not on the 2005 list of Prohibited Substances. See also adrenaline, cathine, ephedrine, methylephedrine.