amphetamines

A group of chemicals belonging to the class of drugs called stimulants. Although their effects are inconsistent, amphetamines act as powerful stimulants on the central nervous system producing feelings of euphoria, aggression, and alertness which may be achieved at the expense of good judgment and selfcriticism. They suppress feelings of hunger and were used in slimming pills. But because they are addictive, amphetamines have been replaced by a number of their derivatives (e.g. fenfluramine). Although not as dangerous as amphetamines, these derivatives, in addition to suppressing appetite, may still induce harmful side-effects (e.g. insomnia, depression, and pulmonary hypertension). In 1996, misuse was linked to 15 deaths in the UK. The General Medical Council advise that amphetamine-style drugs should be used only under expert medical supervision to treat certain forms of obesity.

Amphetamines tend to increase metabolic rate, cardiac output, blood pressure, blood glucose levels, and arousal. Claims that they improve the ability to carry out strenuous physical exercise have not been supported by scientific evidence. These drugs are potentially very harmful. Usage may be followed by severe bouts of depression and dependence. Several fatalities have been attributed to the ability of amphetamines to suppress feelings of fatigue, permitting individuals to overexert themselves to such an extent that they suffer heat stroke and cardiac failure. In 1967, the cyclist Tommy Simpson collapsed during a very long climb in the Tour de France. He died on arrival to hospital. An autopsy revealed that amphetamines almost certainly contributed to his death from heat stroke.

A group of nervous system stimulants that are subject to abuse because of their ability to reduce appetite and produce wake-fulness and euphoria. Abuse of amphetamines may lead to compulsive behavior, paranoia, hallucinations, and suicidal tendencies.

A group of drugs belonging to the stimulants on the World Doping Agency's 2005 Prohibited List. Amphetamines include dextroamphetamine, methamphetamine, methyl phenidate, and phenmetrazine. Although their effects are inconsistent, amphetamines mimic the action of the sympathetic nervous system (hence, they are also known as sympathomimetic amines) acting as powerful stimulants on the central nervous system, producing feelings of euphoria, aggression, and alertness, which may be achieved at the expense of judgement and self-criticism. They suppress feelings of hunger and are components of some slimming pills. Amphetamines tend to increase metabolic rate, cardiac output, blood pressure, blood glucose levels, and arousal. Claims that they improve athletic performance have not been supported by unequivocal scientific evidence. They are potentially very harmful. Administration may be followed by severe bouts of depression and dependence. Several fatalities have been attributed to the ability of amphetamines to suppress feelings of fatigue, permitting individuals to over-exert themselves to the point where they suffer heat stroke and cardiac failure.

Amphetamine