An acute overdose of caffeine, usually in excess of 400 milligrams (more than 3–4 cups of brewed coffee), can result in a state of central nervous system overstimulation called caffeine intoxication. Some people seeking caffeine intoxication resort to insufflation (snorting) of caffeine powder, usually finely crushed caffeine tablets. This induces a faster and more intense reaction. The symptoms of caffeine intoxication are not unlike overdoses of other stimulants. It may include restlessness, nervousness, excitement, insomnia, flushing of the face, increased urination, gastrointestinal disturbance, muscle twitching, a rambling flow of thought and speech, irritability, irregular or rapid heart beat, and psychomotor agitation. In cases of much larger overdoses mania, depression, lapses in judgment, disorientation, loss of social inhibition, delusions, hallucinations, psychosis, rhabdomyolysis, and death may occur.
In cases of extreme overdose, death can result. The median lethal dose (LD50) of caffeine is 192 milligrams per kilogram in rats.The LD50 of caffeine in humans is dependent on weight and individual sensitivity and estimated to be about 150 to 200 milligrams per kilogram of body mass, roughly 80 to 100 cups of coffee for an average adult taken within a limited timeframe that is dependent on half-life. Though achieving lethal dose with caffeine would be exceptionally difficult with regular coffee, there have been reported deaths from overdosing on caffeine pills, with serious symptoms of overdose requiring hospitalization occurring from as little as 2 grams of caffeine.Death typically occurs due to ventricular fibrillation brought about by effects of caffeine on the cardiovascular system.
Treatment of severe caffeine intoxication is generally supportive, providing treatment of the immediate symptoms, but if the patient has very high serum levels of caffeine then peritoneal dialysis, hemodialysis, or hemofiltration may be required.
Caffeine intoxication
Wednesday, November 28, 200718 Experts speak about caffeine
You probably don't drink as much coffee as I drank, but just one caffeinated drink – whether it's a soft drink, caffeinated tea or coffee – will put your body on the caffeine rollercoaster. When you consume caffeine, the drug begins its effects by initiating uncontrolled neuron firing in your brain, according to Stephen Cherniske in his book, Caffeine Blues. This excess neuron activity triggers your pituitary gland to secrete a hormone that tells your adrenal glands to produce adrenalin.
Adrenalin is what gives athletes that winning burst of energy and Good Samaritans the ability to rescue people by lifting cars. Adrenalin is also the source of our "fight-or-flight" response, which enabled our prehistoric ancestors to escape from saber-toothed tigers and other predators. By stimulating your adrenal glands to produce adrenalin, caffeine puts your body in this "fight-or-flight" state, which is useless while you're just sitting at your desk. When this adrenal high wears off later, you feel the drop in terms of fatigue, irritability, headache or confusion.
In other words, caffeine affects your body just like any drug. You start taking it slowly, but as your body develops a tolerance to it, you need more and more to feel the same effects. Eventually, your body reaches a point where it can't be without it; otherwise, you will start to experience withdrawal symptoms.
You may think that you don't drink nearly enough to become addicted to it, but you probably already are. "Careful research conducted by the department of psychiatry and behavioral sciences at Johns Hopkins University School of Medicine shows that low to moderate caffeine intake (as little as one 14-ounce mug per day) can quickly produce withdrawal symptoms," writes Cherniske. Yes, caffeine is a drug, even though it's something that you ingested in your beloved chocolate bars and colas since early childhood.
18 Experts speak about caffeine
"Caffeine's immediate effects on your body"
It doesn't take a genius to see that there might be a downside to all of this neuron activity. In fact, uncontrolled neuron firing creates an emergency situation, which triggers the pituitary gland in the brain to secrete ACTH (adrenocorticotrophic hormone). ACTH tells the adrenal glands to pump out stress hormones—the next major side effect of caffeine.
Caffeine Blues By Stephen Cherniske MS, page 56
Within five minutes after you drink your morning coffee, the caffeine begins to stimulate your central nervous system, triggering the release of stress hormones in your body, causing a stress ("fight or flight" ) response. The stress hormones are useful if you need to prepare yourself to fight or flee a dangerous situation, but if you are simply sitting at your desk you may feel a short charge of alertness, quickly followed by feelings of agitation. Within the next hour or so, after the stress response dissipates, you will probably feel more tired and hungry. At these low-energy times, many people reach for another cup of coffee, or eat a snack that is often high in sugar to "pep up" and stay alert. However, both caffeine and sugar only give you temporary feelings of increased energy, which quickly dissipate. For some people, this cycle of low energy followed by an infusion of caffeine or food continues the entire day -- leaving them feeling exhausted and unable to focus by 3:00 p.m. because they are drained from the ups and downs in energy their body endured throughout the day.
Active Wellness By Gayle Reichler MS RD CDN, page 12
Among other things, it stimulates the production of adrenaline, one of the hormones secreted by the adrenal glands to help us in extreme emergency situations. Our adrenals evolved to give our early ancestors the extra strength and alertness needed to escape a saber tooth tiger attack, but we don't often need that much adrenaline these days. Like sugar, coffee constantly stimulates the production of adrenaline, putting excessive wear and tear on the adrenal glands. And let's not forget that green tea and black tea contain caffeine, and even decaf still contains some caffeine. If you're sensitive to caffeine it can keep you awake at night even if you haven't had any since noon. If you're suffering from insomnia, your best bet is to drink nonstimulating herbal teas such as chamomile or mint in the evening. If you need a boost in the afternoon, try a cup of ginseng tea.
Prescription Alternatives by Earl Mindell RPh PhD and Virginia Hopkins MA, page 388
Caffeine triggers a stress response that involves a surge in adrenal hormones and the classic fight-or-flight "emergency," affecting virtually every cell in the body.
Caffeine Blues By Stephen Cherniske MS, page 98
Everybody "knows" that caffeine makes you more alert and clearheaded. Think again. A cup of coffee gives you a wakeup jolt because it triggers a stress response. Your adrenal glands are prompted to kick out the same stress hormones that are released when you perceive an external threat or danger. Your muscles tense, your blood sugar elevates for extra energy, your pulse and respiration rates speed up, and your state of alertness increases so you're ready to wrestle with or run from environmental dangers. You may be only sitting at your table or desk drinking a cup of coffee, but your body doesn't know that. It's preparing for action.
The Memory Solution by Dr Julian Whitaker, page 261
Caffeine increases the stimulating neurohormone, noradrenaline, and reduces the calming neurotransmitter, serotonin.
The Crazy Makers by Carol Simontacchi, page 191
Caffeine also stimulates the production of norepinephrine, another stress hormone that acts directly on the brain and nervous system. Epinephrine and norepinephrine are responsible for increased heart rate, increased blood pressure, and that "emergency" feeling. In fact, the emergency is quite real. caffeine can trigger a classic fight-or-flight stress reaction with all of the results listed in Illustration.
Caffeine Blues By Stephen Cherniske MS, page 57
I particularly recommend that you avoid caffeine. What caffeine actually does is set off a stress response. It stimulates your adrenal glands to make epinephrine and norepinephrine—the same stress hormones that are produced in response to any stressor. This sets the stress response in motion, causing tense muscles, elevated blood sugar, and increased pulse and respiration. You may feel mentally sharper because your brain is high on adrenaline. It's ready to rumble. One cup of coffee for most people isn't damaging. But as you may recall from our discussion of the three stages of the stress response, if stress hormones remain elevated, the body is thrown into a state of chronic stress. By sipping on coffee, tea, or caffeinated soda all day long, you are forcing your adrenal glands to continue to pump out stress hormones.
The Memory Solution by Dr Julian Whitaker, page 165
Caffeine works by mimicking a hormone that tells the adrenal glands to crank out more adrenaline. The adrenal glands think there is a stressful situation and that they are supposed to be making more adrenal hormone.
Herbal Defense by Ralph T Golan ND, page 280
A dosage of 50 to 100 mg caffeine, the amount in one cup of coffee, will produce a temporary increase in mental clarity and energy levels while simultaneously reducing drowsiness. It also improves muscular-coordinated work activity, such as typing. Through its CNS stimulation, caffeine increases brain activity; however, it also stimulates the cardiovascular system, raising blood pressure and heart rate. It generally speeds up our body by increasing our basal metabolic rate (BMR), which burns more calories. Initially, caffeine may lower blood sugar; however, this can lead to increased hunger or cravings for sweets. After adrenal stimulation, blood sugar rises again. Caffeine also increases respiratory rates, and for people with tight airways, it can open breathing passages. Caffeine is also a diuretic and a mild laxative.
The New Detox Diet by Elson M Haas MD, page 30
Caffeine and nicotine overstimulate the adrenal glands. When these substances, other stressors, and a generally poor diet are combined, the adrenals can enter into a state of emergency. They become depleted of important vitamins, such as B-complex vitamins and vitamin C.
Complete Encyclopedia Of Natural Healing by Gary Null PhD, page 233
Although we think of caffeine in coffee as the "wake-me-up" chemical, chronic use of it may cause fatigue, headache, moodiness, and depression in some people. Because caffeine boosts energy through increasing the production of ATP, the basic unit of energy production in your body, one school of thought suggests that chronically stimulating this system may deplete it, sort of like overworking the soil in farmland. Recommendation: If you are a caffeine junkie (more than 3 cups of coffee a day) and can't get through the day without your coffee fix, you may be promoting your fatigue with caffeine and need a rest period. Go slowly with your reduction to zero caffeine to avoid developing overwhelming sleepiness and a bad headache.
Doctors Complete Guide Vitamins Minerals by Mary D Eades MD, page 324
Caffeine can have a detrimental effect on blood sugar. When caffeine is ingested, the nervous system is stimulated. Adrenaline is released and, in turn, the liver begins to emit stored blood sugar. Insulin is then released, and blood sugar drops below normal—a common seizure trigger for people with epilepsy. Caffeine can also constrict blood vessels in the brain. It is important for people with epilepsy to know that caffeine can be an ingredient in medications, including some antihistamines and decongestants.
Disease Prevention And Treatment by Life Extension Foundation, page 739
For an optimal response to our plan, we recommend eliminating or sharply reducing your caffeine intake. Caffeine raises levels of adrenaline, causes overexcitation, increases stress, and impairs the relaxation response. It's hard to be at peace when you're revved up on caffeine.
Ultraprevention by Mark Hyman MD and Mark Liponis MD, page 241
Watch out for coffee. The caffeine in coffee can upset blood-sugar levels, leaving you fatigued and longing for a quick-pick-me-up snack. Limit coffee to two cups a day.
Food & Mood By Elizabeth Somer MA RD, page 57
Caffeine, in fact, is the most widely used cognitive-enhancement product in our society. Numerous tests have proved that, when used in moderate amounts, caffeine boosts concentration and alertness. Because it is a stimulant, it increases output of adrenaline, and can temporarily improve memory and mood.
Brain Longevity by Dharma Singh Khalsa M.D. with Cameron Stauth, page 266
Caffeine acts directly upon the central nervous system. It brings about an almost immediate sense of clearer thought and lessens fatigue. It also stimulates the release of stored sugar from the liver, which accounts for the "lift" coffee, cola, and chocolate give. But these benefits may be far outweighed by the side effects:
Vitamin Bible for the 21st Century by Earl Mindell, page 315
Caffeine Addiction
Caffeine is a xanthine alkaloid compound that acts as a psychoactive stimulant and diuretic in humans. The word comes from the French term for coffee, café.[2] Caffeine is also called guaranine when found in guarana, mateine when found in mate, and theine when found in tea; all these names are considered chemical synonyms for the same chemical compound.
Caffeine is completely absorbed by the stomach and small intestine within 45 minutes of ingestion. After ingestion it is distributed throughout all tissues of the body and is eliminated by first-order kinetics.
The half-life of caffeine—the time required for the body to eliminate one-half of the total amount of caffeine consumed at a given time—varies widely among individuals according to such factors as age, liver function, pregnancy, some concurrent medications, and the level of enzymes in the liver needed for caffeine metabolism. In healthy adults, caffeine's half-life is approximately 3–4 hours. In women taking oral contraceptives this is increased to 5–10 hours, and in pregnant women the half-life is roughly 9–11 hours.Caffeine can accumulate in individuals with severe liver disease when its half-life can increase to 96 hours. In infants and young children, the half-life may be longer than in adults; half-life in a newborn baby may be as long as 30 hours. Other factors such as smoking can shorten caffeine's half-life.
Caffeine is metabolized in the liver by the cytochrome P450 oxidase enzyme system (specifically, the 1A2 isozyme) into three metabolic dimethylxanthines, which each have their own effects on the body:
* Paraxanthine (84%): Has the effect of increasing lipolysis, leading to elevated glycerol and free fatty acid levels in the blood plasma.
* Theobromine (12%): Dilates blood vessels and increases urine volume. Theobromine is also the principal alkaloid in cocoa, and therefore chocolate.
* Theophylline (4%): Relaxes smooth muscles of the bronchi, and is used to treat asthma. The therapeutic dose of theophylline, however, is many times greater than the levels attained from caffeine metabolism.