The alkaloid caffeine is a fairly common substance in nature. In ordinary life, depending on the chosen diet, we get it with various foods. In tea leaves, its content reaches 4%, in coffee seeds - up to 2%, the amount of caffeine in cola nuts reaches 6%, and in cocoa beans - up to 4%. Medicine considers caffeine as a classic stimulant. His ability to “boost” the work of the nervous system, reduce fatigue, increase mental activity and drive away sleep has long been noticed by man and is widely used in practice.
Caffeine exhibits its stimulating effect due to the fact that it has a blocking effect on adrenaline receptors - the central nervous system mediator. In addition, caffeine has a direct stimulating effect. Like all methylxanthines, it is able to block an enzyme that limits the transmission of nerve impulses at the cellular level. In other words, any stimulus significantly enhances its effect on nerve cells.
But besides natural, so-called food, suppliers, you can get caffeine in tablets. In this case, we are dealing with a pure substance. The effect that the tablets produce is longer, while its effect is less pronounced. We will not get an instant temperature jump with a fast heartbeat, as from the use of ordinary coffee. Caffeine tablets contain 0.2 g of active substance, its effect is equivalent to taking any energy drink in an amount of 0.7 l. The effect of taking pure caffeine lasts from 5 to 7 hours. Taking three tablets in a row can provoke arrhythmia. This substance was previously prescribed by prescription. Caffeine in tablets is now sold freely, and its price is cheap. All responsibility for its proper use lies with the buyers themselves.
Lovers of stimulating drinks - tea and coffee, will find caffeine in tablets as sacrilege over an ancient ceremony. But it is known that athletes give preference to precisely calculated, akin to the medical, method of caffeine consumption. This substance, due to its stimulating effect, is widely used in training athletes. Its ability to “disperse” the body increases the efficiency of each workout, promotes increased breakdown of fat, allows you to have a significant impact on the result in the competition.
And even the introduction of restrictions on the caffeine content in urine makes it easy to undergo a doping control, despite its maximum concentration in the diet of athletes on the eve of serious performances. The maximum dosage of a substance is from six to nine milligrams per kilogram of weight, depending on the level of preparation and specialization of the athlete, but even this amount of the substance taken makes it easy to keep the caffeine concentration in the analyzes at an acceptable level.
Caffeine is also used in the treatment of a number of diseases. Instructions on this list include diseases that depress the activity of the central nervous system and cardiovascular system. A positive effect of taking this drug is observed in the treatment of arterial hypotension, asthenic syndrome, cerebral vasospasms.
I found widespread use of caffeine in tablets in cases where it is necessary to increase mental and physical performance, eliminate drowsiness, it is given to children with enuresis.
Caffeine is contraindicated in conditions of increased arousal, in cases of sleep disturbance and arterial hypertension. It is not recommended for diseases of the cardiovascular system, atherosclerosis, glaucoma, the elderly and children under five years of age.