Stimulant drugs nature

Caffeine is the most widely consumed stimulant drug in the world. It occurs naturally in coffee, tea, and the cola nut and is added to many soft drinks. Many of us consume coffee and soft drinks because of the desirable stimulatory effects produced by caffeine many of us have consumed too much caffeine and felt the consequences. The undesirable effects of caffeine, the agitation, the inability to concentrate, the mild tremors, and the general unpleasantness, are a form of neurotoxicity. Literally your brain, and more specifically, the adenosine receptors in your brain, has too much caffeine. These effects are a reversible form of neurotoxicity. Fortunately, we metabolize caffeine quickly and the undesirable effects end. By experience we have learned how to moderate our caffeine consumption to avoid the unpleasant side effects. A great deal of money is made from the neuroactive and physiological effects of caffeine. You can learn more about this fascinating drug in the chapter on caffeine. 

Table 15.2 provides just a few examples of different neuroactive agents and their mechanism of action. Caffeine, the most widely consumed stimulant drug in the world, works by affecting the adenosine receptor. Adenosine is a naturally occurring depressant, so caffeine works by blocking the depressive actions of adenosine, causing stimulation. 

Caffeine, the primary stimulant found naturally in coffee, tea, and chocolate, is artificially added to many other products, such as soft drinks, over the counter stimulants, cold remedies, and pain relievers. It is the worlds most widely used drug. Different types of coffee contain different amounts of caffeine, and different brewing techniques lead to further variations in content. Depending on the type of coffee (an arabica coffee contains about half the caffeine of a robusta) and the fineness of the grounds, the drip method of brewing leads to 110 to 150 mg of caffeine per cup. Instant coffee has 40-108 mg of caffeine per cup. 

Caffeine is an addictive drug used in soft drinks as a stimulant. It occurs naturally in coffee, tea, and chocolate. 

When Montgomery and I published our article, we thought we had disproven another theory of placebo effects - the theory that placebo effects are produced by the release of endorphins in the brain. In 1978 researchers at the University of California in San Francisco discovered that when placebos reduce pain, they may stimulate the release of endorphins.18 Endorphins, the existence of which had only been discovered a few years earlier, are opioids that are produced naturally by the brain. Just like the opiates that are derived from opium - morphine and codeine, for example - endorphins reduce the sensation of pain. The University of California researchers reasoned that if placebos can mimic the effects of opiate drugs, maybe they do so by stimulating the release of the brain s endogenous opioids. 

Some of these natural products—and drugs made from them—are known collectively as the ergot alkaloids, and have found use in medicine. Ergonovine, for example, is a selective stimulant for contraction of uterine muscle and is used in conjunction with labor and delivery. A mixture of hydrogenated ergot alkaloids—reduced at the 9,10-position—has found... 

The pleasure derived from using tobacco is linked to the stimulation of dopamine-dependent neurotransmitter pathways in the brain, particularly in the meso-limbic system. The precise nature of this link remains controversial, but many of the neurophysiological processes underlying nicotine addiction are common to other addictive drugs with diverse pharmacological actions such as opiates, cannabis, alcohol and cocaine. 

---