What type of stimulant is caffeine

what type of stimulant is caffeine

Caffeine Addiction and Abuse

Mar 19, †Ј Caffeine is a central nervous system stimulant. It works by stimulating the brain. Caffeine is found naturally in foods and beverages such as coffee, tea, colas, energy and chocolate. Jun 03, †Ј What is caffeine? Caffeine is a natural stimulant most commonly found in tea, coffee, and cacao plants. It works by stimulating the brain and .

Caffeine is a central nervous system CNS stimulant of the methylxanthine class. There are several known mechanisms of action to explain the effects of caffeine. The most prominent is that it reversibly blocks the action of adenosine on its receptors and consequently prevents the onset of drowsiness induced by adenosine.

Caffeine also stimulates certain portions of the autonomic nervous system. Caffeine is a bitter, white crystalline purinea methylxanthine alkaloidand is chemically related to the adenine and guanine bases of deoxyribonucleic acid DNA and ribonucleic acid RNA. It is found in the seeds, nuts, or leaves of a number of plants native to Africa, East Asia and South America, [12] and helps to protect them against herbivores and from competition by preventing the germination of nearby seeds.

People may drink beverages containing caffeine to relieve or prevent drowsiness and to improve cognitive performance.

To make these drinks, caffeine is extracted by steeping the plant product in water, a process called infusion. Caffeine-containing drinks, such as coffeeteaand colaare consumed globally in high volumes. Inalmost 10 million tonnes of coffee beans were consumed globally. Caffeine can have both positive and negative health effects.

It can treat and prevent the premature infant breathing disorders bronchopulmonary dysplasia of prematurity and apnea of prematurity.

Evidence of a risk during pregnancy is equivocal; some authorities recommend that pregnant women limit caffeine to the equivalent of two cups of coffee per day or less. Toxic doses, over 10 grams per day for an adult, are much higher than the typical dose of under milligrams per day.

Thus it requires roughly 50Ч ordinary cups of coffee to reach the toxic dose. However, pure powdered caffeine, which is available as a dietary supplementcan be lethal in tablespoon-sized amounts. Caffeine is a central nervous system stimulant that reduces fatigue and drowsiness. Caffeine can delay or prevent sleep and improves task performance during sleep deprivation. A systematic review and meta-analysis from found that concurrent caffeine and L -theanine use has synergistic psychoactive effects that promote alertness, attention, and task switching ; [40] these effects are most pronounced during the first hour post-dose.

Caffeine is a proven ergogenic aid in humans. Caffeine improves muscular strength and power, [48] and may enhance muscular endurance. While this effect is not present during exercise-to-exhaustion exercise, performance is significantly enhanced.

This is congruent with caffeine reducing perceived exertion, because exercise-to-exhaustion should end at the same point of fatigue. For the general population of healthy adults, Health Canada advises a daily intake of no more than mg.

In healthy children, moderate caffeine intake under mg produces effects that are "modest and typically innocuous". Based on average body weights of children, this translates to the following age-based intake limits: [54]. Health Canada has not developed advice for adolescents because of insufficient data. However, they suggest that daily caffeine intake for this age group be no more than 2. This is because the maximum adult caffeine dose may not be appropriate for light-weight adolescents or for younger adolescents who are still growing.

The daily dose of 2. This is a conservative suggestion since older and heavier-weight adolescents may be able to consume adult doses of caffeine without suffering adverse effects.

The metabolism of caffeine is reduced in pregnancy, especially in the third trimester, and the half-life of caffeine during pregnancy can be increased up to 15 hours as compared to 2. The UK Food Standards Agency has recommended that pregnant women should limit their caffeine intake, out of prudence, to less than mg how to do a cover letter for a job caffeine a day Ч the equivalent of two cups of instant coffee, or one and a half to two cups of fresh coffee.

There are conflicting reports in the scientific literature about caffeine use during pregnancy. Coffee and caffeine can affect gastrointestinal motility and gastric acid what is oil well fracking. Acute ingestion of caffeine in large doses at least Ч mg, equivalent to the amount found in 2Ч3 cups of coffee or 5Ч8 cups of tea results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks.

However, chronic users of caffeine develop a tolerance to this effect and experience no increase in urinary output. Minor undesired symptoms from caffeine ingestion not sufficiently severe to warrant a psychiatric diagnosis are common and include mild anxiety, jitteriness, insomnia, increased sleep latency, and reduced coordination.

Increased consumption of coffee and caffeine is associated with a decreased risk of depression. Some textbooks state that caffeine is a mild euphoriant, [85] [86] [87] others state that it is not a euphoriant, [88] [89] and one textbook states in one place that caffeine is not a euphoriant but in another place groups it among euphoriants.

Whether caffeine can result in an addictive disorder depends on how addiction is defined. Compulsive caffeine consumption under any circumstances has not been observed, and caffeine is therefore not generally considered addictive.

Caffeine does not appear to be a reinforcing stimulus, and some degree of aversion may actually occur, with people preferring placebo over caffeine in a study on drug abuse liability published in an NIDA research monograph. However, its addition was contested with claims that this diagnostic model of caffeine addiction is not supported by evidence.

Withdrawal can what is f and b mild to clinically significant distress or impairment in daily functioning. Tolerance to the effects of caffeine occurs for caffeine-induced elevations in blood pressure and the subjective feelings of nervousness. Sensitizationthe process whereby effects become more prominent with use, occurs for positive effects such as feelings of alertness and wellbeing.

Non-regular caffeine users have the least caffeine tolerance for sleep disruption. A protective effect of caffeine against Alzheimer's disease and dementia is possible but the evidence is inconclusive. Caffeine increases intraocular pressure in those with glaucoma but does not appear to affect normal individuals.

The DSM-5 also includes other caffeine-induced disorders consisting of how to make udu walalu anxiety disorder, caffeine-induced sleep disorder and unspecified caffeine-related disorders. Consumption of 1Ч1. Caffeine overdose can result in a state of central nervous system over-stimulation known as caffeine intoxication, a clinically significant temporary condition that develops during, or shortly after, the consumption of caffeine.

According to the DSM-5, caffeine intoxication may be diagnosed if five or more of the following symptoms develop after recent consumption of caffeine: restlessness, nervousness, excitement, insomnia, flushed face, diuresis increased production of urinegastrointestinal disturbance, muscle twitching, rambling flow of thought and speech, tachycardia increased heart rate or cardiac arrythmia, periods of inexhaustibility, and psychomotor agitation.

Death from caffeine ingestion appears to be rare, and most commonly caused by an intentional overdose of medications. High caffeine consumption in energy drinks At least 1 liter or mg of caffeine was associated with short-term cardiovascular side effects including hypertension, prolonged QT interval and heart palpitations. These cardiovascular side effects were not seen with smaller amounts of caffeine consumption in energy drinks less than mg.

Since there is no antidote nor reversal agent for caffeine intoxication, treatment of mild caffeine intoxication is directed toward symptom relief; severe intoxication may require peritoneal dialysishemodialysisor hemofiltration. Caffeine is a substrate for CYP1A2and interacts with many substances through this and other mechanisms. According to DSSTalcohol provides a reduction in performance and caffeine has a significant improvement in performance. Caffeine antagonizes the activational aspect of behavioral control, but has no effect on the inhibitory behavioral control.

Birth control pills can extend the half-life of caffeine, requiring greater attention to caffeine consumption. Caffeine sometimes increases the effectiveness of some medications, such as those for headaches.

The pharmacological effects of adenosine may be blunted in individuals taking large quantities of methylxanthines like caffeine. In the absence of caffeine and when a person is awake and alert, little adenosine is present in CNS neurons. With a continued wakeful state, over time adenosine accumulates in the neuronal synapsein turn binding to and what is baracks middle name adenosine receptors found on certain CNS neurons; when activated, these receptors produce a cellular response that ultimately increases drowsiness.

When caffeine is consumed, it antagonizes adenosine receptors; in other words, caffeine prevents adenosine from activating the receptor by blocking the location on the receptor where adenosine binds to it.

As a result, caffeine temporarily prevents or relieves drowsiness, and thus maintains or restores alertness. Caffeine is an antagonist of adenosine A 2A receptorsand knockout mouse studies have specifically implicated antagonism of the A 2A receptor as responsible for the wakefulness-promoting effects of caffeine. Antagonism of adenosine receptors by caffeine also stimulates the medullary vagal, vasomotor, and respiratory centerswhich increases respiratory rate, reduces heart rate, and constricts blood vessels.

Heart palpitations are caused by blockade of the A 1 receptor. Because caffeine is both water- and lipid-soluble, it readily crosses the bloodЧbrain barrier that separates the bloodstream from the interior of the brain.

Once in the brain, the principal mode of action is as a nonselective antagonist of adenosine receptors in other words, an agent that reduces the effects of adenosine.

The caffeine molecule is structurally similar to adenosine, and is capable of binding to adenosine receptors on the surface of cells without activating them, thereby acting as a competitive antagonist. In addition to its activity at adenosine receptors, caffeine is an inositol trisphosphate receptor 1 antagonist and a voltage-independent activator of the ryanodine receptors RYR1RYR2and RYR3. While caffeine does not directly bind to any dopamine receptorsit influences the binding activity of dopamine at its receptors in the striatum by binding to adenosine receptors that have formed GPCR heteromers with dopamine receptors, specifically the A 1 Ч D 1 receptor heterodimer this is a receptor complex with 1 adenosine A 1 receptor and 1 dopamine D 1 receptor and the A 2A Ч D 2 receptor heterotetramer this is a receptor complex with 2 adenosine A 2A receptors and 2 dopamine D 2 receptors.

Caffeine also causes the release of dopamine in the dorsal striatum and nucleus accumbens core a substructure within the ventral striatumbut not the nucleus accumbens shellby antagonizing A 1 receptors in the axon terminal of dopamine neurons and A 1 Ч A 2A heterodimers a receptor complex composed of 1 adenosine A 1 receptor and 1 adenosine A 2A receptor in the axon terminal of glutamate neurons.

Caffeine, like other xanthinesalso acts as a phosphodiesterase inhibitor. Caffeine from coffee or other beverages is absorbed by the small intestine within 45 minutes of ingestion and distributed throughout all bodily tissues. Caffeine's biological half-life Ч the time required for the body to eliminate one-half of a dose Ч varies widely among individuals according to factors such as pregnancy, other drugs, liver enzyme function level needed for caffeine metabolism and age.

In healthy adults, caffeine's half-life is between 3 and 7 hours. Caffeine is metabolized in the liver by the cytochrome P oxidase enzyme system, in particular, by the CYP1A2 isozyme, into three dimethyl xanthines[] each of which has its own effects on the body:.

Caffeine can accumulate in individuals with severe liver diseaseincreasing its half-life. A review found that increased caffeine intake was associated with a variation in two genes that increase the rate of caffeine catabolism. Subjects who had this mutation on both chromosomes consumed 40 mg more caffeine per day than others. The xanthine core of caffeine contains two fused rings, a pyrimidinedione and imidazole. The pyrimidinedione in turn contains two amide functional groups that exist predominantly in a zwitterionic resonance the location from which the nitrogen atoms are double bonded to their adjacent amide carbons atoms.

Hence all six of the atoms within the pyrimidinedione ring system are sp 2 hybridized and planar. The biosynthesis of caffeine is an example of convergent evolution among different species.

Caffeine may be synthesized in the lab starting with dimethylurea and malonic acid. Commercial supplies of caffeine are not usually manufactured synthetically because the chemical is readily available as a byproduct of decaffeination. Extraction of caffeine from coffee, to produce caffeine and decaffeinated coffee, can be performed using a number of solvents. Following are main methods:. One study found that decaffeinated coffee contained 10 mg of caffeine per cup, compared to approximately 85 mg of caffeine per cup for regular coffee.

Caffeine can be quantified in blood, plasma, or serum to monitor therapy in neonatesconfirm a diagnosis of poisoning, or facilitate a medicolegal death investigation. Some analog substances have been created which mimic caffeine's properties with either function or structure or both.

Of the latter group are the xanthines DMPX [] and 8-chlorotheophyllinewhich is an ingredient in dramamine. Members of a class of nitrogen substituted xanthines are often proposed as potential alternatives to caffeine. Caffeine, as do other alkaloids such as cinchoninequinine or strychnineprecipitates polyphenols and tannins.

What Is Caffeine Addiction?

Mar 30, †Ј Caffeine is a central nervous system stimulant that has the ability to enhance concentration, increase metabolism, and boost mood. Whether it comes from coffee, tea, energy drinks, or soda, many people feel like they УneedФ caffeine in the morning to increase alertness and the motivation to work. Mar 24, †Ј Caffeine has many effects on your body's metabolism. It. Stimulates your central nervous system, which can make you feel more awake and give you a boost of energy. Is a diuretic, meaning that it helps your body get rid of extra salt and water by urinating more. Caffeine is a major component of coffee, tea and chocolate and in humans acts as a central nervous system (CNS) stimulant. Consumption of caffeine, even in high doses, has not been associated with elevations in serum enzyme elevations or instances of clinically apparent liver injury.

Caffeine is naturally found in the leaves and fruits of some plants. It is in coffee, black and green tea, cocoa, cola soft drinks and energy drinks. It may also be in chocolate bars, energy bars and some non-prescription medications, such as cough syrup and slimming tablets.

Guarana a popular additive in energy drinks is also a natural source of caffeine. Caffeine is a stimulant, which means it increases activity in your brain and nervous system. It also increases the circulation of chemicals such as cortisol and adrenaline in the body.

In small doses, caffeine can make you feel refreshed and focused. In large doses, caffeine can make you feel anxious and have difficulty sleeping. Caffeine is well absorbed by the body, and the short-term effects are usually experienced between 5 and 30 minutes after having it. These effects can include increased breathing and heart rate, and increased mental alertness and physical energy. Depending on the individual, these effects can last up to 12 hours.

How you react to caffeine depends on your body mass, health and metabolism. It also depends on whether your body is used to getting regular doses of caffeine and how much you have in one serving. Research suggests that mg per day or less is an acceptable dose of caffeine for the general population. Energy drinks contain caffeine, as well as ingredients such as taurine and guarana a natural source of caffeine.

Energy drinks do not hydrate and should not be confused with sports drinks. The caffeine and sugar content of energy drinks is high. In fact it is often higher than in soft drinks. The levels of caffeine in energy drinks vary between brands, so it is important to read the label before having them. This means you become used to its effects on your body and need to take larger amounts to achieve the same results.

Over time, you may become physically and psychologically dependent on caffeine to function effectively. If you are dependent on caffeine and you stop having it, you may experience withdrawal symptoms. These may include:. This gives your nervous system time to adapt to functioning without the drug.

However, check the anti-doping rules of your particular sporting code to make sure caffeine is not a restricted drug for the sport you play. This page has been produced in consultation with and approved by:. The size of a standard drink can vary according to the type of alcohol.

Amphetamines are psychostimulant drugs that speed up the workings of the brain. Prolonged misuse of steroids can cause liver damage and severe mood swings. Benzodiazepines tranquillisers are highly addictive and should only be used for certain conditions in a short-term or emergency situation.

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Skip to main content. Home Drugs. Actions for this page Listen Print. Summary Read the full fact sheet. On this page. What does caffeine do to your body?

How much caffeine is okay each day? Energy drinks and caffeine Caffeine dependency and withdrawal Children, pregnant women, athletes and caffeine Where to get help. Some of the signs and symptoms of having too much caffeine include: a rise in body temperature frequent urination dehydration dizziness and headaches rapid heartbeat palpitations restlessness and excitability anxiety and irritability trembling hands sleeplessness first feeling energetic but then having an even greater feeling of tiredness.

Approximate caffeine levels per serve include: chocolate drinks: 5Ч10mg per ml instant coffee: 80Чmg per ml drip or percolated coffee: Чmg per ml espresso coffees such as espresso or latte: Чmg per ml decaffeinated coffee: 2Ч6mg per ml black tea: 65Чmg per ml cola drinks: 40Ч49mg per ml Red Bull energy drink: 80mg per ml energy drink: mg per ml dark chocolate bar: mg per 55g serve milk chocolate bar Ч 10mg per 50g serve guarana: can contain up to mg per 1g of guarana caffeine tablets such as No-Doz Ч mg per tablet.

Energy drinks and caffeine Energy drinks contain caffeine, as well as ingredients such as taurine and guarana a natural source of caffeine. Children and pregnant women should avoid drinking energy drinks.

These may include: fatigue crankiness persistent headache sweating muscle pain anxiety. Symptoms of caffeine withdrawal may begin within 12 to 24 hours and can last about seven days. Children, pregnant women, athletes and caffeine Some people who need to take special care with caffeine include: children Ч currently there are no guidelines for children's intake of caffeine.

Caffeine intake should be investigated if children are showing symptoms of irritability, inability to sleep, interrupted sleep or stomach upsets. Remember that caffeine is present in many soft drinks and chocolate, not just coffee and tea. The consumption of energy drinks should also be closely monitored pregnant women Ч if you are pregnant , limit your caffeine intake to mg per day or less, or avoid it altogether. Having high amounts of caffeine may increase your risk of miscarriage, experiencing a difficult birth and having a baby with a low birth weight athletes Ч caffeine is not classified as a prohibited substance under the World Anti-Doping Code Prohibited List.

Where to get help Your GP doctor Pharmacist. Caffeine , , European Food Safety Authority. Caffeine facts , , Alcohol and Drug Foundation. Give feedback about this page. Was this page helpful? Yes No. View all drugs. Related information. Support groups Family Drug Help. From other websites Dietitians Association of Australia.

DrugInfo, Caffeine facts.. Content disclaimer Content on this website is provided for information purposes only. Reviewed on:

4 thoughts on “What type of stimulant is caffeine

  1. You can also slide your finger to the right, doesnt have to be the left. more of a personal preference thing i believe

  2. Thanks for clarifying, the reason i downloaded because the original instruction was required.

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