Amphetamine

Amphetamine is a central nervous system (CNS) stimulant that releases euphoric sensations and increases mental and physical performance, overcoming fatigue. The compound imitates natural stimuli, such as food and water, that signal and allow the release of dopamine in the central nervous system. It has been previously prescribed to alleviate pain, especially in the 1960s, when American pharmaceutical companies distributed the drug widely and readily, eventually leading to widespread amphetamine abuse and the categorization of the compound as a schedule II drug in the United States. More recently, amphetamine has been used, with Food and Drug Administration (FDA) approval, to treat attention-deficit hyperactivity disorder (ADHD), narcolepsy, and obesity caused by external lifestyle factors. Non-FDA-approved uses include prescription for treatment-resistant depression.

Brief History

The use and production of stimulant compounds are as old as human records have been kept. More than five thousand years ago, Chinese physicians would use the stimulant ma huang—also known as ephedra, a preparation of the Ephedra sinica plant—for weight loss and appetite suppression. In the 1880s, Japanese chemist Nagayoshi Nagai successfully synthesized methamphetamine from ma huang after discovering ephedrine, an amphetamine substitute, to be a primary and active agent in the compound. In 1887, Romanian chemist Lazăr Edeleanu produced amphetamine, but the compound’s effects on the central nervous system were not revealed until the 1930s, after which reports of amphetamine abuse began to rise.

Amphetamine, like other fatigue-combating drugs, increases the concentration of dopamine in the synaptic gap, or the space between the cell membrane of an axon terminal and the target cell, which allows a nerve cell (neuron) to pass electrical or chemical signals to other nerve cells. Dopamine increases the survival of an organism by aiding its attentiveness and learning to identify the natural threats against survival. It is a natural neurotransmitter that signals the brain to release sensations of pleasure following stimuli such as food and water.

Drug substances can imitate the action of neurotransmitters, block their synthesis, stimulate or enhance their release, or interfere with their reabsorption (reuptake) in order to prolong their action. Amphetamines have structures similar to that of dopamine and can use proteins known as dopamine transporters to diffuse through the nerve cell membrane into the terminal button of the presynaptic region. Upon reaching the presynaptic region, amphetamines reverse the mechanism of the dopamine transporter to eject dopamine molecules out of their respective storage units and travel into the synaptic gap, ultimately increasing the dopamine concentrations in that gap. The presence of amphetamine also reduces dopamine reuptake and constrains the production of monoamine oxidase A (MAO-A), an enzyme that eliminates dopamine and increases violent tendencies. Likewise, amphetamines use glutamate neurons to excite dopamine-connected neurons by removing any inhibitory effects, thus allowing the dopaminergic neurons to be easily available. The uptake of amphetamine increases the release of dopamine, simulating the presence of natural stimuli to increase the body’s pleasure sensations.

Impact

Amphetamine affects the central nervous system by generally increasing the body’s alertness, available energy, and emotional stability and presenting a sense of euphoria. Amphetamine abuse can improve a person’s performance, provide a feeling of euphoria, and in some cases encourage anorexia. Amphetamine abuse has been a widespread problem given its high toxicity levels and the resulting abnormalities in the brain’s structure. Adult amphetamine abusers have lower gray-matter volume and higher striatal volumes in their brains, decreasing effective muscle control and sensory perceptions, while compensating for the excess dopamine. Children who were exposed to higher levels of amphetamine in utero have lower striatal volumes and often develop white-matter abnormalities that affect the central nervous system.

Amphetamine and stimulant pills became readily available in the United States in the late 1960s, after which stimulant abuse abruptly increased. In the 1970s, amphetamine production was reduced by at least 80 percent, and the FDA categorized it as a schedule II drug, based on its stronger potential for addiction, in the hopes of greatly minimizing the widespread addiction occurring across the country. Once amphetamine was rescheduled, doctors became more cautious when prescribing it for clinical use.

Due to its effectiveness in increasing energy and improving performance, amphetamine abuse tends to be more prevalent in three main groups of people: the military, athletes, and students. Amphetamines were previously used during World War II to enhance soldier alertness during battle and to fight mental and physical fatigue. As amphetamines were distributed by the members of the US and British armies, the German and Japanese militaries followed suit, distributing methamphetamine to their brigades, thus spreading and starting the use of stimulant drugs by military forces.

Amphetamines restore performance skills that have been degraded by sleep deprivation or circadian-rhythm-related deficiencies. However, the combination of sleep deprivation and stimulant drugs may have antagonistic effects, such as enhanced paranoia.

Amphetamine use among American athletes was first reported in the 1940s for American football and in the 1950s for other sports. Sleep deprivation and muscular pain are common among athletes. For many, the effects of amphetamines in combating these ailments and increasing attention, focus, energy, self-confidence, and mood outweighed the adverse health effects that followed. By the 1970s, deaths among athletes had begun to be associated with improper use of amphetamines, as high blood pressure caused by the combination of amplified exercise performance and peripheral vasoconstriction, which prevents the body from cooling down, can lead to heatstroke or cardiac arrest. Augmented euphoria often masks the body’s senses to the normal bodily warnings, deterring any possible signals of cardiac arrests.

Students and professionals who abuse amphetamines often do so for the effective increases in productivity and concentration that they provide. Students may use amphetamines as a study aid, believing that they increase one’s alertness and ability to maintain information for longer periods of time. Dependency on amphetamines or other stimulants has been shown to increase rates of binge drinking, cannabis use, and cocaine use and to increase the chances of heart attack or stroke in longtime users.

Bibliography

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