Caffeine psychoactive substance

Caffeine is the most widely consumed psychoactive substance. Peak plasma caffeine is reached between 15 and 120 minutes after oral ingestion in humans at doses of 5-8 mg/kg. The caffeine half-life ranges from 0.7 to 1.2 h in rodents, from 3 to 5 h in monkeys, and from 2.5 to 4.5 h in humans (Nehlig 1999). 

In order to limit this ambiguity, the terms psychoactive substances (referring to licit and illicit substances, e.g., caffeine and nicotine but also cannabis and heroin) and dmgs of abuse (referring only to recreational dmgs, e.g., cocaine, cannabis, etc.) will be used throughout the present work. 

Caffeine is probably the most widely used psychoactive substance in the world and is commonly used to combat sleepiness. A variety of studies have shown it to be effective in reducing sleepiness and enhancing performance, at least when used acutely (47 48). These studies have demonstrated dose-dependent enhanced... 

Abstinence means no use of psychoactive substances. However, in our culture, or for that matter in any culture, psychoactive substances are virtually impossible to avoid. Nearly all of us have experienced pain medication. Most soft drinks, tea, and, of course, coffee contain caffeine, a potent stimulant. Yet, individuals who partake of these will consider themselves abstinent and with few exceptions this use is marginal to the point of not being worth consideration. 

Caffeine is currently the most widely used psychoactive substance in the world." In the United States, 80% to 90% of adults regularly consume behaviorahy active doses of caffeine." Although research has shown that caffeine can cause a compulsive pattern of use, the prevalence of caffeine dependence and its clinical significance are difhcult to determine. 

Caffeine is the most widely used psychoactive substance. Besides its well-known presence in coffee, tea, colas, and chocolate, it is available in many over-the-counter and prescription oral medications and as injectable caffeine sodium benzoate (occasionally used for neonatal apnea). Caffeine is widely used as an anorectant, a... 

A generic term relating to psychological and/a physical dependence when one or mae psychoactive substances or classes of psychoaaive substances are abused (alcohol sedatives, hypnotics and anxiolytics cannabis opioids cocaine amphetamine and other sympathomimetics hallucinogens caffeine nicotine ... 

As a recreational substance, alcohol is second only to caffeine in worldwide use and second only to tobacco in health costs from abuse. In recent years, the American public has received a mixed message on alcohol s health benefits and deficits. Wine is said to help protect moderate drinkers from heart disease, but at the same time, alcoholism is responsible for more substance-related deaths than all other psychoactive drugs combined, with the exception of tobacco. Although there are few pharmacotherapies for alcoholism and alcohol abuse, a multimillion dollar project has been funded at the University of California at San Francisco by Gallo Wine and the state of... 

In the preceding chapter we said alcohol, nicotine, and caffeine are the most popular psychoactive drugs. Of the three, alcohol has been known, manufactured, and used the longest by far. Most important, diis drug has had profound influences on the societies around the world in which it is used. Alcohol actually refers to several substances—for example, isopropyl alcohol (rubbing alcohol), methyl alcohol (wood alcohol), and ethanol. Ethanol is the alcohol we drink, and in this text the word alcohol means ethanol unless otherwise specified. 

Caffeine is the most popular psychoactive stimulant. This xanthine alkaloid occurs in coffee, tea, and cola beverages. At a modest dose of 100-200 mg, it enhances wakefulness and reduces fatigue. However, intake of higher quantities (>500 mg/day) can cause addiction. Other psychostimulant substances include deanol, pemoline, and their derivatives. These substances have limited clinical apphcation. The structures of caffeine. 

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